Talk:Nonmetal

Goldhammer-Herzfeld ratio for graphene and black phosphorus

The Goldhammer-Herzfeld ratio for an element = R/V where R is the isolated atom’s molar refractivity and V is the molar volume for the bulk element. The ratio has no units. It is a simple measure of how metallic an element is, metals having values ≥ 1. It is proportional to density (Edwards & Sienko 1983).

Graphene

The ratio for carbon as diamond is ca. 0.62

The density of diamond is 3.514 g cm⁻³

It is known one square metre of graphene would weigh 0.77 mg

The C—C bond length in graphene is 1.4210 x 10^-8 cm,^ which translates to the thickness of monolayer graphene. The volume involved is therefore 100 cm x 100 cm x 1.421 x 10⁻⁸ cm = 1.421 x 10^-4 cm³

^ In stark contrast, the distance between each layer in graphite is 3.25 × 10^-8 cm.

The density of graphene is therefore its weight divided by its volume = 0.77 mg/1.421 x 10^-4 cm³ = 5.419 g cm⁻³

The GH ratio for a graphene layer, within which electron delocalisation occurs in graphite, is therefore (density graphene/density diamond) × ratio for diamond = (5.419/3.514) × 0.62 = ca. 0.95

Black phosphorus

The ratio for white P is ca. 0.57

The density of white P is 1.8232g cm⁻³

That for black P is 2.69

The ratio for black P is therefore (density black P/density white P) × ratio for white P = (2.6/1.8232) × 0.57 = ca. 0.84

Selenium

The ratio for Se₈ is ca. 0.77

The density of Se₈ is 4.4 g cm⁻³

That for gray Se is 4.802

The ratio for gray Se is therefore (density gray Se/density Se₈) × ratio for Se₈ = (4.802/4.4) × 0.77 = ca. 0.84

References

• Density values: Wiberg N 2001, Inorganic Chemistry, Academic Press, San Diego, pp. 575, 680, 785
  
• Ratio values: Edwards PP & Sienko MJ 1983, "On the occurrence of metallic character in the periodic table of the elements", Journal of Chemical Education, vol. 60, no. 9, pp. 692–693, doi:10.1021/ed060p691
• Weight of graphene: "Class for Physics of the Royal Swedish Academy of Sciences" 2010, "Graphene," The Royal Swedish Academy of Sciences, Stockholm, viewed August 13, 2021
  
• C—C bond length in graphene: Hill G & Holman J 2000, Chemistry in Context, 5th ed., Nelson Thornes, Cheltenham, p. 124

First sentence

MOS:FIRST suggests that:

• The first sentence should tell the nonspecialist reader what or who the subject is, and often when or where.
• It should be in plain English.
• If its subject is definable, then the first sentence should give a concise definition: where possible, one that puts the article in context for the nonspecialist.

In plain English, it's preferable to define things in terms of what they are rather than what they aren't.

So the Nonmetal first sentence now reads as follows:

"In chemistry, a nonmetal is a chemical element that is lighter than iron, that is brittle or crumbly if solid or frozen, and that forms an acid or an oxide if it reacts with nitric acid."

I used "that" three times, in imitation of the definition of a planet in the lede of the article of the same name.

The definition first refers to the relative lightness of nonmetals since the heaviness of naturally occurring metals such as gold, copper, and iron may have been noticed in prehistory and, in light of their malleability, led to the first attempts to craft metal ornaments, tools, and weapons. All metals discovered from then until 1809 had relatively high densities; their heaviness was regarded as a singularly distinguishing criterion.

Among other nonmetallic elements, the definition accommodates the noble gases, the halogen gases F and Cl, the halogen liquid Br, and the residual nonmetallic gases H, N and O, since these are all crumbly if frozen. The definition further includes physical and chemical properties, as would seem to be appropriate in a chemistry context.

Note that noble gases do not react with nitric acid so that the last part of the definition does not apply to them. This is OK though since they're lighter than iron and crumbly when frozen.

"Acid", "oxide" and "nitric acid" could be said to be technical terms however these are allowed in plain English if there's no plainer equivalent. They're wikilinked in any event.

The word count of the lede paragraph has been reduced by about one-third.

Sandbh (talk) 00:12, 30 January 2022 (UTC)

While I agree that a positive definition is generally better than a negative one, that preference is not found in MOS:FIRST. This sentence has one explicit AND, another implicit one, three ORs and two IFs. And I note that it requires an explanation on this talk page to convince the knowledgeable editor that the noble gases satisfy the description.

This is not a definition but a complicated description that practically speaking requires boolean algebra analysis to apply in any specific situation. Compared to this the previous 1st sentence is simplicity itself.

Plain English is not simply a matter of avoiding technical vocabulary. It also requires simple, easy to follow sentence structure. This sentence does not qualify as "plain English", and so does not meet the MOS.

The example you cite planet is instructive. It gives the generic class and then says which things in that class do not qualify.

A planet is a large astronomical body that is not a star or stellar remnant.

The comparable lede would be

A nonmetal is a chemical element that is not a metal or a metalloid.

Simplicity itself. But because of the ambiguity with metallois I would prefer something like this:

A nonmetal is a chemical element which does not have the properties common to metals.

There is no commonly accepted definition of nonmetal. But everyone agrees that they are not metals.

Please restore plain English to the first sentence.

YBG (talk) 06:57, 30 January 2022 (UTC)

Arbitrary break

Thanks YBG. I appreciate your interest and taking the time to post your concerns. I note you concur that a positive definition is preferred.

MOS:FIRST provides that the first sentence “should be in plain English.”

In plain English, it's preferable to express things in terms of what they are rather than what they aren't. It also seems to me that defining a nonmetal as something that is a not a metal is a redundancy that is further inconsistent with the spirit of plain English. It further imparts nothing to the reader since it requires them to know what the (common) properties of a metal are. Probably most people do and since two of these properties are a shiny appearance and good electrical conductivity there is scope to erroneously conclude that graphite (carbon) is a metal.

Given the idea of a definition expressed in terms what a nonmetal is, the next task is to write it as plainly as possible.

I posted an explanation here as a matter of courtesy since the definition has been subject to some to’ing and fro’ing.

I’ve since simplified the definition, and made it less specific, so it now reads:

A nonmetal is a relatively light chemical element that is brittle or crumbly if solid or frozen, and that forms an acid or an oxide if it reacts with nitric acid. (31 words)

@Sandbh: I strongly suggest removing relatively light, as it is not accurate for all the nonmetals. At least, nobody would agree that iodine, xenon, or radon are relatively light, and relatively is subjective anyway (with respect to iron? tin? oxygen?). ComplexRational (talk) 15:55, 30 January 2022 (UTC)

Thanks @ComplexRational: I feel it's relevant to note that ca. 80% of nonmetals have a density < 5 gm/cm³ and ca. 80% of metals have a density > 5 gm/cm³. The intended meaning of "light", given most metals are heavy, is "low density". In what sense were you saying no one would agree that I, Xe or Rn are relatively light? The "relatively" qualifier is there in the sense that there is no rigorous definition of a nonmetal. The situation is the same in chemistry with regard to what is a metal(?), there being no rigorous definition. Thus the topic sentence of the next paragraph in the nonmetal lede says, "While the term dates from at least 1708, it has no widely-agreed precise definition." OTOH metals have an average density of ca. 9.5 gm/cm3 whereas the nonmetal average is ca 1.8 gm/cm3, noting there are light metals such beryllium, magnesium and aluminium, and relatively heavier nonmetallic elements such as antimony, and tellurium. Sandbh (talk) 22:27, 30 January 2022 (UTC)

When I read relatively light, I interpret it to mean "having relatively low mass" (i.e., low atomic mass, which I, Xe, and Rn certainly do not have). If "having relatively low density" was instead the intended meaning, I would suggest rewording or relocating. This ties in with YBG's comment: especially in the opening sentence, we want a definition that accurately describes an element if and only if it is a nonmetal – "relative" definitions can be fleshed out and clarified elsewhere in the article. ComplexRational (talk) 01:49, 31 January 2022 (UTC)

@ComplexRational: I've replaced "light" with low density, and further generalized and streamlined the definition. I hope the updated version works for you. Sandbh (talk) 23:37, 31 January 2022 (UTC)

Better now. I'm also guessing that "where applicable" implies the exception of noble gases? ComplexRational (talk) 15:20, 1 February 2022 (UTC)

@ComplexRational: Yes, that’s it. Sandbh (talk) 22:28, 1 February 2022 (UTC)

Boolean algebra is not required. The definition (now) has a simple and relatively easy to follow sentence structure. It is written in plain English, noting that technical terms are permitted in plain English where there are no plainer equivalents. Since the subject matter itself is technical, a few technical terms ought to be less than controversial.

Regarding your concerns about the definition of a planet given at the planet article, here’s the definition I was comparing the nonmetal definition to:

"A planet is a non-stellar body that is massive enough to be rounded by its own gravity, that directly orbits a star, and that has cleared its orbital zone of competing objects.” (32 words)

The question of what is a nonmetal is a complex area and I’ve tried to address this as plainly as possible, with a view to avoiding redundancy and minimising scope for unnecessary confusion.

Could you please consider my response and reconsider your request. Thank you Sandbh (talk) 09:35, 30 January 2022 (UTC)

Sandbh (talk) 09:35, 30 January 2022 (UTC)

Note

• A description presents the characteristics and aspects of that which is being described in sufficient detail that the audience can form a mental picture, impression, or understa≥nding of it.
• A definition is a statement of the meaning of a term (a word, phrase, or other set of symbols).

I remain convinced that a negative definition is vastly superior to a description that contains nested ANDs & ORs. YBG (talk) 16:19, 30 January 2022 (UTC)

Meaning of definition

YBG, on what fundamental basis are you saying there is a difference between "definition" and "description"?

Meanings of "definition" include mentions of "descriptions", for example:

• "…extensional definitions (which try to list the objects that a term describes)" – See "definition"
• "In mathematics, definitions are generally not used to describe existing terms, but to describe or characterize a concept." – See "definition"
• "a description of the features and limits of something" – Cambridge Dictionary
• "a statement that describes what something is" – Merriam Webster
• "a defining; a description of a thing according to its properties" – The Chambers Dictionary.

The nub of these meanings is to define what a thing is, according to its features, properties and limits, rather than what it is not.

In a similar descriptive manner, here's the IUPAC recommended definition of a hydrogen bond:

"The hydrogen bond is an attractive interaction between a hydrogen atom from a molecule or a molecular fragment X–H in which X is more electronegative than H, and an atom or a group of atoms in the same or a different molecule, in which there is evidence of bond formation."

Curiously, the origin of definition is late Middle English: from Latin definitio(n- ), from the verb definire ‘set bounds to’ (see define). Thus, the nonmetal definition attempts to set bounds to what is a nonmetal.

Could you let me know what a "nested AND" is, and where the "nested ANDs" are?

1. There may be scope to remove one of the "ORs" as follows:

"A nonmetal is a relatively light chemical element that is mechanically weak, and that forms an acid or an oxide if it reacts with nitric acid." (26 words)

I'm not sure if "mechanically" is quite the right term since the intending meaning is that nonmetals (normally) have no structural strength.

2. There may be scope to remove the other "OR" as follows:

"A nonmetal is a relatively light chemical element that is mechanically weak, and that forms an acidic compound if it reacts with nitric acid." (23 words)

Sandbh (talk) 01:00, 31 January 2022 (UTC)

The first sentence now reads:

In chemistry, a nonmetal is a type of chemical element generally characterized by low density, low strength, and a tendency, where applicable, to form acidic compounds.

I hope that works for you. Sandbh (talk) 23:37, 31 January 2022 (UTC)

This is much better. I'm wondering if the final clause is even necessary in the lede sentence. Certainly the noble gasses are both low density and low strength. If that clause were placed later in the paragraph, you would avoid the "where applicable" language which seems a bit troublesome.

As to the issue of definition vs. description (the topic of this section, from which the discussion has wandered): this is a meta-discussion which I think is no longer necessary here. We could, if you wish, continue it in user space or off-wiki.

YBG (talk) 08:00, 2 February 2022 (UTC)

Good to hear from you YBG. As you implied that final cause isn't necessary. So I removed it and added a sentence about the reactivity of the nonmetals, that addresses the noble gas question. I'll pass on the definition vs. description question. Sandbh (talk) 07:38, 4 February 2022 (UTC)

New lead sentence, 19 March 2022

The lead sentence has been recently changed to read "a nonmetal is a chemical element that is typically a colorless or colored gas, such as oxygen or chlorine, and a poor conductor of heat and electricity." I see at least two major problems with this phrasing. First, nonmetals are a variety of elements of different states of matter, so we should not open by emphasizing gases, even if a majority are gases, because this is an incomplete and misleading definition of what a nonmetal is. Second, "colorless or colored" describes a set and its complement, so can be interpreted as "a nonmetal is a chemical element that is typically a gas", which is both a vague and inaccurate description. I haven't modified anything myself because of all the discussions regarding the lead; further discussion and suggestions are welcome. Pinging Sandbh and YBG. ComplexRational (talk) 16:13, 19 March 2022 (UTC)

ComplexRational did you happen to view my first suggestion at Wikipedia:Peer review/Nonmetal/archive2#First paragraph again? I am concerned that I may be spinning my wheels as a non-chemist if others aren't also engaging at the peer review; I'll wait for this to be sorted before I continue at the PR. I was just preparing to start a line-by-line review ... SandyGeorgia (Talk) 16:23, 19 March 2022 (UTC)

@SandyGeorgia: I didn't have the PR on my watchlist, so I don't think I saw your suggestion until just now. My thoughts are pretty much the same as yours: a broad statement qualifying what a nonmetal is. Should I copy-paste this comment to that page to keep the discussion in one place?

Also, as much as I'd like to engage, I don't expect to have any significant free time for the next two months, so my contributions there will likely only be a few isolated comments and responses. Moreover, I'm happy to offer a second opinion on more generic content (or some crossovers with physics), but I'm also a non-chemist with just a casual interest in the topic. ComplexRational (talk) 18:08, 19 March 2022 (UTC)

ComplexRational Yes, it might be optimal to keep comments on the peer review, but now that this is here, copying it over would just create a jumble. It might be clearer if, once we get this sorted, I just add a link there back to this discussion here, so everything is included without the need to copy. I understand you're busy, but appreciate you keeping an eye on things as you are able; few science-minded editors have the clarity of prose that you do, and I have No Clue when it comes to Chemistry! I kind of liked my attempt at the first paragraph of the lead, but what do I know :) SandyGeorgia (Talk) 18:36, 19 March 2022 (UTC)

I agree that the current led sentence is problematic for all the reasons you have mentioned. Exacerbating this is the presence of the word "typically". YBG (talk) 01:03, 20 March 2022 (UTC)

@YBG and ComplexRational: does the version I first proposed here work, and if not, could you suggest improvements to it? SandyGeorgia (Talk) 01:09, 20 March 2022 (UTC)

@SandyGeorgia: Here's my tweak of your first suggestion:

In chemistry, nonmetals are a type of chemical element are usually lower than metals in weight, structural strength, shininess, and ability to conduct heat and electricity. They don't have the characteristics of metals, which are typically shiny silvery-gray solids; moderate to good conductors; and can be molded, shaped or hammered into thin wires or threads without crumbling or shattering. Nonmetals may have a metallic, colorless or colored appearance, with about half being gases and half being brittle to crumbly solids. They are moderate to high in electronegativity; their atoms cannot easily attract electrons.

YBG (talk) 02:53, 20 March 2022 (UTC)

The last clause should rather be "their atoms can easily attract electrons". :) Double sharp (talk) 04:38, 20 March 2022 (UTC)

Oopsie ... my typo, that got propagated. SandyGeorgia (Talk) 04:41, 20 March 2022 (UTC)

YBG, a missing word that after element? Otherwise looks good to me. I know that Sandbh was concerned not to define nonmetals as what they are not, as the second sentence does, but that seems unavoidable. After all, their name is nonmetal. SandyGeorgia (Talk) 03:12, 20 March 2022 (UTC)

The proposed adaption is unintentionally misleading where it says, "They don't have the characteristics of metals, which are typically shiny silvery-gray solids; moderate to good conductors." C, a nonmetal, is a shiny gray solid and a good conductor. H, a nonmetal, is a moderately good conductor of heat. These problems go away by distinguishing between typical and less typical nonmetals, consistent with the fact that nonmetals show a variation in the degree of their nonmetallic character. Describing nonmetals in terms of what they aren’t is not plain English, and should be mostly avoidable, in my view, with careful crafting. Sandbh (talk) 07:28, 20 March 2022 (UTC)

I intend to shortly post some thoughts on the background to the evolution of the lede. For now, please note that I’ve further refined the lede paragraph. Sandbh (talk) 02:38, 20 March 2022 (UTC)

This lead paragraph is focused on some specific elements, without providing the broad and general definition as in YBG's more general adaptation of the lead I proposed. I don't understand it. SandyGeorgia (Talk) 03:54, 20 March 2022 (UTC)

Initial (quick) thoughts:

The most recent version of the lede is written for the lay reader per SandyGeorgia’s idea. It starts with the basics and then progressively fills in the rest of the details. The idea is to provide the lay reader with a tangible sense of what nonmetals are.

I thought I had it down pat yesterday but changed my mind after reading it on my phone. I feel this current version, linked by SG, now does the job for the lay reader.

YBG, the context for “typical” is that metals are typically solid, shiny, plastic, and good conductors. Conversely, the “typical” nonmetals (H, N, O, S, F, Cl, Br, He, Ne, Ar, Kr, Xe, Rn) are not solid, not shiny, not plastic, and poor conductors (of electricity).

That just leaves the shiny nonmetals C, P, Se and I; and the part-time nonmetals err metalloids B, Si, Ge, As, Sb, Te. There are no poor conductors here: C, As, Sb are metallic conductors; the rest are semiconductors consistent with their shiny appearance. Sandbh (talk) 06:34, 20 March 2022 (UTC)

I don't like "Rounding out the field"; are nonmetals a field? It sounds odd. And aren't solids, liquids and gases states of matter rather than a fundamental characteristic? Graham Beards (talk) 06:42, 20 March 2022 (UTC)

Thanks Graham. All metals we know of are solids apart from Hg. Conversely, the nonmetals that are not shiny are all gases, apart from Br and S. For the lay reader I feel that counts as a fundamental and characteristic difference. Your thoughts?. Sandbh (talk) 07:10, 20 March 2022 (UTC)

They are not fundamental. In my view the fundamental difference is the metallic bond and the presence of the Fermi gas in metals. The tensile strength of metals, their high melting point , opacity, ductility and conductance are all because of that bond and an understanding of the metallic bond requires quantum theory. Non-metals (and the term is informal) show a broader variety of properties because of they way they are bonded and this is the fundamental difference. The Lead seems to be dodging this because it is deemed to be too technical perhaps? But I see no way round it. As it stand, the article is not accurate and this is a major problem. Don't dump accuracy in favour of simplicity or you might just as well say metals are made by elves and non-metals are made by pixies. Graham Beards (talk) 08:07, 20 March 2022 (UTC)

Is it possible to jam a layperson-understandable explanation of Fermi gases and metallic bonds into a footnote? Think African humid period and TRAPPIST-1 as examples. Jo-Jo Eumerus (talk) 11:02, 21 March 2022 (UTC)

Suggestion for the lede, based on what I wrote at Periodic table#Metallicity and what we currently have:

“ A nonmetal is a chemical element that generally lacks metallic properties. Nonmetals are often liquids or gases at room temperature, and are brittle when solid. Many have low densities, poor thermal and electrical conductivity, and lack metallic lustre. Chemically, they usually have moderate to high electronegativity, i.e. a tendency to attract electrons: this rationalises their properties, as it makes it difficult for them to lose electrons and engage in metallic bonding. In the periodic table, nonmetallic character tends to increase as one goes from bottom to top and left to right; nonmetals are thus mostly clustered in the top-right corner.

Although the majority of elements are metals, many nonmetals are among the most common elements in Earth and the universe. Two nonmetals, hydrogen and helium, make up about 99% of ordinary matter in the observable universe by mass. Five nonmetallic elements, hydrogen, carbon, nitrogen, oxygen and silicon, largely make up the Earth's crust, atmosphere, oceans and biosphere.

Most nonmetals have biological, technological or domestic roles or uses. Living organisms are composed almost entirely of the nonmetals hydrogen, oxygen, carbon, and nitrogen. Near-universal uses for nonmetals are in medicine and pharmaceuticals; lasers and lighting; and household items.

While the term non-metallic dates from at least 1566, there is no widely-agreed precise definition of a nonmetal. Elements near the borderline between metals and nonmetals on the periodic table often have properties characteristic of both categories, so that different classifications can be justified by different criteria. Consequently, which elements are recognised as nonmetals depends on the classification criteria used by each author. Fourteen elements are effectively always included and up to about nine more elements are frequently to sometimes added, as shown in the accompanying periodic table extract. Some authors classify borderline elements into an intermediate category of metalloids or semimetals.

”

This is of course just a statement of "tendencies". Given all the edge cases everywhere, I think it's a better approach than listing individual cases. It can be argued that C, As, Sb, and Bi are only forming quasi-metallic structures anyway, since the atoms are not equivalently positioned and metallic conduction comes from interactions between the layers, so even the simplification has a grain of truth to it. (Though since Po is more metallic than Bi, it's still a simplification.) Double sharp (talk) 07:58, 20 March 2022 (UTC)

• Sigh. Is this still in there? First paragraph? Once more:

Both state of matter (SoM) and color are, per the article itself, non-defining and even non-descriptive appearances. Their relation to being a nonmetal is not even described or based in the article body. It is not stated as classifying metal/nonmetal property (not in the body, so not in a source then). They are not listed in any of the § Chemical and § Suggested distinguishing criteria "some ..." (ouch) properties lists. Being science, still no predictions are (can be) made for lesser known elements. For edxample, what about the heavy halogens and nobles? How can they be excluded/included from these statements/claims/notes if there is no scientific base for these two properties?

It has, by the authors Sandbh's own article writing, no place in the article, and so no reason to even be referred to in the lede. At all. The continuous wrangling with the writing is a prohibitive sign that it is not yet of encyclopedic level or GA stability. The fact that the lede is (still) problematic in this, is an issue for the current peer revieuw. -DePiep (talk) 08:41, 20 March 2022 (UTC)

Colour is, indeed, irrelevant. Cu, Cs, and Au are clearly metals and equally clearly coloured.

State of matter is slightly less irrelevant, because being a liquid/gas at r.t. usually means that a metallic state is thermodynamically unstable. Then again, it means that a large macromolecular structure is also thermodynamically unstable. And in any case this should be explained. Double sharp (talk) 08:55, 20 March 2022 (UTC)

Re Double sharp's proposed text at 07:58, which I generally like (pending resolution of color), but some comments:

1. See #"Near-universal" below.
2. The first sentence is fine for a paragraph within the body of Periodic table. But for the first sentence of the lead here, it says nothing except a nonmetal is not a metal, which is not entirely helpful for what will be coughed up by Google. It could benefit from one more clause that gives a "such as" overview of the mentioned properties.
3. Please avoid using i.e. in the lead (or in articles, for that matter).
4. "Rationalizes their properties" will be lost on layreaders ... first paragraph for a concept taught in high school needs to be accessible.

SandyGeorgia (Talk) 15:18, 20 March 2022 (UTC)

Thanks for all the comments, suggestions and ideas. Since nonmetals, in chemistry, are those judged to have a predominance of applicable properties, the lede sentence now simply says just that:

"In chemistry, a nonmetal is a chemical element judged to have a predominance of characteristic properties such as being transparent or colored; having a low weight; low to no structural strength; poor thermal conductivity; poor electrical conductivity; low melting point; low boiling point; and a tendency to form acidic compounds."

This is an accurate statement of the situation, largely written in plain English, for the lay reader, in accordance with WP policy.

I’ve retained "colour" since 4 of 23 elements or 1 in 6 of elements within scope of the article are colored; conversely the fact that 3 of 95 or ca. 1 in 32 metals are known to be coloured is effectively meaningless. Color for nonmetals is significant in that the band gaps of the semiconducting elements P, Se, I, B, Si, Ge, and Te are less than the visible spectrum cut off of ca. 1.8 ev, hence their metallic appearance. Conversely the band gaps for red P and S (yellow), for example, are greater hence their coloured appearance.

For context, the rest of the lede’s first paragraph says:

"Solid nonmetals, such as graphitic carbon and sulfur, are brittle to crumbly, and cannot be hammered into sheets or easily drawn into wires without shattering or breaking. Nonmetal atoms are moderate to high in electronegativity; they tend to easily attract electrons."

The “negative” reference to "not being hammered into sheets or easily drawn into wires" is not plain English, but this is probably unavoidable.

Other characteristic properties such as bonding types, oxidation numbers, and cation/ion formation are included later in the article.

Double sharp: I’ll later look closer, if I may, at your mention of elements close to the border between metals and nonmetals. Sandbh (talk) 12:09, 20 March 2022 (UTC)

I’ve abandoned the idea of defying nonmetals in terms of what they are. Picking up on Double sharp’s suggestion, and SG’s comment, the lede paragraph now reads:

“In chemistry, a nonmetal is a chemical element that generally lacks a predominance of metallic properties. They are nearly all gases or solids at room temperature, such as oxygen or sulfur. The only liquid nonmetal, bromine, is usually topped by a layer of its fumes. They typically lack the shiny appearance of metals, have low weight, and are poor thermal and electrical conductors. The solid nonmetals are brittle to crumbly, cannot be flattened into sheets or easily drawn into wires without shattering or breaking, and have low to no structural strength. Nonmetal atoms are moderately to highly electronegative; they tend to attract electrons in chemical reactions and to form acidic compounds.”

— Preceding unsigned comment added by Sandbh (talk • contribs)

I still feel that the topic should be defined before branching into specific examples or elements, which only confuses the layreader. At least move sentences two and three to the end, after the definition, but reading about a layer of fumes at the very beginning of the article is just odd. SandyGeorgia (Talk) 02:01, 21 March 2022 (UTC)

SandyGeorgia: To some extent, as you alluded earlier, a nonmetal is something that is not a metal. The implication being that metals have so shaped civilisations over thousands of years that everyone, including lay readers, know that metals are shiny, usually heavy, and good conductors of heat (a hot car under the sun) and electricity (lightning rods, etc). So the term “nonmetal” just by itself conveys much information already. The Br mention is meant to suggest that while Br is the only liquid metal, it is so volatile that one usually encounters it together with its fumes i.e. gaseous vapours. So the nonmetals are almost all either gases or solids, unlike the metals which are all solids, bar one. Otherwise, having to account for Br as the only liquid nonmetal becomes rather exasperating in terms of prose construction. I’ll look at this some more along the lines of your suggestion, and maybe post, revert, and ping you a link, if something good comes of it (or not). Sandbh (talk) 03:37, 21 March 2022 (UTC)

SandyGeorgia: I moved sentences 2 and 3 further down, reordered then, and joined some other sentences so there are now only four sentences left:

1. In chemistry, a nonmetal is a chemical element that generally lacks a predominance of metallic properties; they are typically transparent or non-metallic in appearance, have low weight, and are poor thermal and electrical conductors.
2. Solid nonmetals are brittle to crumbly, cannot be flattened into sheets or easily drawn into wires without shattering or breaking, and have low to no structural strength.
3. The rest of the nonmetals are nearly all gases at room temperature (the only liquid nonmetal, bromine, is usually topped by a layer of its own fumes).
4. Nonmetal atoms are moderately to highly electronegative; they tend to attract electrons in chemical reactions and to form acidic compounds.

So the result is now a definition that is more than negative in expression, followed by the physical distinction between the solids and the rest, and closing with two chemical properties. I hope you like it. Sandbh (talk) 05:37, 21 March 2022 (UTC)

I find this version digestible, clear, thorough and understandable as a non-chemist (although I still think the fumes are adding verbiage that is unnecessary and lost on a general audience). If others are satisfied, I'll continue tomorrow (doc app't today) my line-by-line, at the peer review, but wish others would be watching as well. SandyGeorgia (Talk) 14:50, 21 March 2022 (UTC)

That’s beaut! I’ll remove mention of the fumes and see if this can be better placed in the nonmetal halogens section. Sandbh (talk) 23:03, 21 March 2022 (UTC)

Arbitrary break

Double sharp, fyi that I’ve incorporated your good suggestions here to the extent that I feel is practical and appropriate. I’m reluctant to say something in the lede about "metalloids" as a sometimes third class (notwithstanding they behave chemically as nonmetals) given the lede is supposed to give the lay reader an overall impression of the subject matter, and it currently does that. In my view, more details about the pesky or mysterious metalloids can be left to the main body of the article, as is currently the case. Sandbh (talk) 03:57, 21 March 2022 (UTC)

"Near-universal"

While you all sort the ongoing issues with the definition in the lead, I will postpone my line-by-line at the peer review, where I had next planned to tackle clarity of prose. A good deal of progress has been made, but the article is yet a long ways from FAC ready.

But as long as we're looking at the lead, can this (as a sample of lacking prose clarity) be sorted:

• Near-universal uses for nonmetals are in medicine and pharmaceuticals; lasers and lighting; and household items.

What does "near-universal" refer to? Does it mean almost every nonmetal is used in at least one of these applications, or does it mean that almost every one of these applications involves a nonmetal? The reader should not have to stop, in the lead, to sort out what a sentence is saying. As written, it is adding nothing but confusion to my layreader knowledge, and could be re-written in plainer language. SandyGeorgia (Talk) 15:09, 20 March 2022 (UTC)

Oh! You thanked me :) before I’d gotten round to saying I’d fixed this. Nicely spotted BTW. Sandbh (talk) 03:14, 21 March 2022 (UTC)

"by each author"

• which of these borderline cases are counted as nonmetals can vary depending on the classification criteria used by each author.

Is "by each author" redundant ? Other than that, I'm satisfied with the readability of the lead and will move on to the body starting tomorrow. I am still concerned about the "always, frequently, sometimes" construct, as it may still feel too synth-y to get by FAC, but I will propose a way to fix that on the peer review page. Sorry to be working so piecemeal, but that is the luxury that peer review affords, over FAC, and is a good thing. SandyGeorgia (Talk) 00:36, 22 March 2022 (UTC)

Trimmed. Agree about PR v FAC. Sandbh (talk) 23:26, 29 March 2022 (UTC)

Lede suggestions: Trim, poor conductor first, and "Nonmetal element"

As a first-time reader, the lede is clear and well-crafted, but the following things jump out:

1. In the first sentence, stating the poor electrical and thermal conductivity would be much more helpful than the rather technical mention of tending to form acidic compounds, which makes the noble gasses and ammonia feel unwelcome. The pure semiconductors are poor conductors compared to metals, and carbon's exceptional behavior shouldn't take away from beginning the article with the main idea for a general audience.

   I mention a tendency to form acidic compounds as I feel it's important to say something about the chemistry of the nonmetals. I haven't included poor electrical conductivity in the first sentence of the lede since graphite is a rather good electrical conductor, and arsenic and antimony, which are sometimes counted as nonmetals, are rather OK such conductors. For thermal conductivity, metals range from 6.3 W m⁻¹ K⁻¹ to 429 for silver. The thermal conductivities of the following nonmetallic elements fall within this range: B, C, Si, Ge, P, As, Sb. The third sentence in the lede does say however, "Unlike metals, most nonmetals are poor conductors of heat and electricity."

2. This lede sentence is more distracting than helpful:
    "This is so even though the number of nonmetal elements is several times lower than the number of metal elements"
   Simply cutting it would make the paragraph stronger. The brief discussion that precedes it makes very clear the overwhelming importance of the four named nonmetals.

   That sentence no longer exists.

3. Changing the article title to "Nonmetal element" would be helpful. The first sentence of the lede makes clear that this is specifically about elements, but then abandons any readers who are looking to learn about materials that are non-metals in general; they have to scan the whole article to find out that compounds and molecular materials are simply not covered, and then begin a hunt for another article. Metal covers all metallic materials, elemental or not, and the change in scope between that and Nonmetal is puzzling.

   The first sentence of the lede makes its scope clear: "In chemistry, a nonmetal is a type of chemical element..." My feeling is that the most popular use of the term nonmetal is in the sense of chemical elements. I don't know of a field of study that is devoted to "nonmetal(lic) materials" which would presumably cover e.g. ceramics and glasses, plastics, composites, foams, textiles and presumably nonmetallic liquids and gases. Sandbh (talk) 05:16, 23 February 2022 (UTC)

I made no edits to the article because I note that the solicitation for FAC nomination for this article has begun. If suggestions are not helpful at this time because they disrupt that process, then please ignore for now. –MadeOfAtoms (talk) 10:48, 4 February 2022 (UTC)

Withdrawn by the nominator, as the editor requested to have comments at the talk page. CactiStaccingCrane (talk) 00:05, 10 February 2022 (UTC)

GA Reassessment

This discussion is transcluded from Talk:Nonmetal/GA2. The edit link for this section can be used to add comments to the reassessment.

Notifying @Sandbh:.

Look, I know that you have worked on an article so hard, yet the article gets reassessed and it seems like no one cares about you. But, I really do understand your stress, and thus I don't nominate Nonmetal for community assessment, because surely the FAC people will batch you into death. I want this article to be way better than this now. And you are not alone, I also has SpaceX Starship being culled for review even after so many months of work.

Anyways, the primary reason I want to reassess the article is at criteria 1a (the prose is clear, concise...), 1b (complies with the manual of style guidelines...) and 3a (it addresses the main aspects of the topic) at here. I have a feeling that this article is written in a way that break the prose badly, shown one example below (criteria 1a + 1b):

---

The distinction between metals and nonmetals arose, in a convoluted manner, from a crude recognition of natural kinds of matter. Thus:

• matter could be divided into pure substances and mixtures;
• pure substances eventually could be distinguished as compounds and elements;
• "metallic" elements seemed to have broadly distinguishable attributes that other elements did not...

---

I also has concerns at the comprehensiveness of the article. What are the enormous uses of the nonmetals? How does nonmetals are discovered since the ancient times? Why do the nonmetal criteria is so convoluted? How about bio-compatibility? There's much to discuss. (criterion 3a)

I want to mention accessibility and layout problems as well, but that's for another time. There's a ton of work to do already :) CactiStaccingCrane (talk) 16:16, 9 February 2022 (UTC)

Speedy keep and close this GAR

I see no reasons for a GAR on this article at all. I don't think CactiStaccingCrane is capable of appraising the prose given the gibberish they have written on this page. What on Earth does "How does nonmetals are discovered since the ancient times?" mean? The question is totally incomprehensible. The review of SpaceX Starship has absolutely nothing to do with this article or its GA status. This nomination just comes across as some sort of convoluted tit for tat and is disruptive editing. Graham Beards (talk) 18:51, 9 February 2022 (UTC)

Ok, whatever. If you guys don't like it, then there's no reason for me to continue further. CactiStaccingCrane (talk) 00:04, 10 February 2022 (UTC)

Speedy keep and close this WP:IGF GAR
I intend to edit the article in light of feedback rec’d at FAC #4, and to then list it for the second time at PR. Concerns of the kind raised above, if still outstanding, can be listed in that forum. Sandbh (talk) 23:04, 9 February 2022 (UTC)

Peer review

• The article is in Peer review since 22 February 2022. -DePiep (talk) 07:04, 23 April 2022 (UTC)

FAC5 (27 August 2022)

This article is WP:FAC per 27 August 27, 2022. See Wikipedia:Featured_article_candidates/Nonmetal/archive5. DePiep (talk) 05:38, 3 September 2022 (UTC)

Copyedit

Following the FAC which closed without consensus to promote, Sandbh has asked me to take a look at the prose. I am delighted to accept; this is an important article on a subject I am fascinated by and which is dear to me. Could I ask regular editors to watch what I am doing; even though I have read the FAC and this talk page, I might inadvertently change the meaning in a way which leaves it untrue to the sources, which in most cases I will not have read. (I doubt it, but you never know.) I might start in the next day or two. Just keep me right, ok? John (talk) 16:08, 29 September 2022 (UTC)

@John: I'll be happy to keep an eye out for factual accuracy in the background, but I can't promise a solid time commitment at the moment. ^Complex/_Rational 19:38, 29 September 2022 (UTC)

Many thanks to User:John for your gracious acceptance, and to User:ComplexRational for your offer to maintain a watch on factual accuracy. Sandbh (talk) 04:30, 30 September 2022 (UTC)

• @John: While I am happy to learn (the language) from your edits, I want to note that other longer term issues regarding this article are of encyclopedic nature, and probably cannot be resolved by improving language. -DePiep (talk) 15:46, 30 September 2022 (UTC)

• Thank you. Yes, I am getting a feeling for that as I start to trim at it. Is there anything particular that you have in mind? John (talk) 15:50, 30 September 2022 (UTC)

  No nothing particular. I note that after this June 2021 version, the article has undergone a full rewrite, as in: from scratch. Also, there are multiple FAC and similar targeted discussions since. Well, one piece de resistance I know of: while color and state of matter are not defining nor distinguisihing for nonmetals, and not analysed as related to nonmetal-ness in the body, these properties keep appearing in the first sentence. This does not seem like an incident, but a pattern (the property–classification setup). Alas, maybe we'll meet again over this. DePiep (talk) 16:52, 30 September 2022 (UTC)

  Interesting. Here is a first sample batch of copyedits. Somewhat of a feeling of déjà vu as I remember copyediting metalloid back in the day, I think, and it had similar problems to this. Is this an article about the concept of nonmetallicity? Or a survey of the various nonmetals and their chemical and physical properties? To what extent should we try to carry along the general reader into tricky ideas like electronegativity? I need to have a long, hard think about this one. Luckily there is no deadline. John (talk) 16:25, 2 October 2022 (UTC)

Thanks John.

It may help to change the article name to Nonmetal (chemical element). This would set out the scope of the article better e.g. plastics, woods and stones, all of which are "nonmetals" in a broad sense, are excluded. This problem doesn't arise with "metalloid" because of the strong association of that word with silicon and germanium etc.

For EN, Jensen (1996, p. 11) asserted that "no concept more thoroughly pervades the fabric of modern chemistry". I'd add, "aside from the periodic table and probably the concepts of acids and bases, and metals and nonmetals". The simple EN rubric is that metals have low EN and nonmetals have high EN. While there is some overlap between the two zones, as tends to be the case for all single criteria, it works well enough for most purposes. Sandbh (talk) 00:41, 3 October 2022 (UTC)

Some comments about the sample batch of copy edits to follow. Sandbh (talk) 00:41, 3 October 2022 (UTC)

Sample batch of copy edits

Line 35

Before:
In chemistry, a nonmetal is a chemical element that generally lacks a predominance of metallic properties...

After:
A nonmetal is a chemical element that lacks a predominance of metallic properties...

I think that exclusion of In chemistry, a works only if the name of the article becomes "Nonmetal (chemical element)". I included the generally qualifier to indicate that this was a qualitative judgement. Sandbh (talk) 01:01, 3 October 2022 (UTC)

---

Before:
Nearly all nonmetals have individual uses in medicine and pharmaceuticals; lighting and lasers; and household items.

After:
Nearly all nonmetals have uses in medicine and pharmaceuticals; lighting and lasers; and household items.

I included "individual" as not all nonmetals have uses in all three areas. Sandbh (talk) 01:01, 3 October 2022 (UTC)

---

Before:
Some elements have a marked mixture of metallic and nonmetallic properties;

After:
Some elements have a mixture of metallic and nonmetallic properties;

Virtually all elements, to varying degrees, have a mixture of metallic and nonmetallic properties. Only a few have such a mixture to a marked extent. Sandbh (talk) 01:01, 3 October 2022 (UTC)

Line 48

Before:
A nonmetal is a chemical element that has, among other properties, a relatively low density and moderate to high electronegativity. More generally, they lack a preponderance of more metallic attributes such as luster, deformability, good thermal and electrical conductivity, and low electronegativity.

After:
A nonmetal is a chemical element that has low density and moderate to high electronegativity. They also lack metallic attributes such as luster, deformability, good thermal and electrical conductivity, and low electronegativity.

Tricky. The "after" version does not quite work, since quite a few nonmetals have luster (e.g. C, black P, Se and I) and C, As, Sb are pretty good electrical and thermal conductors. Sandbh (talk) 02:35, 3 October 2022 (UTC)

---

Before:
Fourteen effectively always recognized as such are hydrogen, oxygen, nitrogen, and sulfur; the corrosive halogens fluorine, chlorine, bromine, and iodine; and the noble gases helium, neon, argon, krypton, xenon, and radon (see e.g. Larrañaga et al).

After:
Fourteen almost always recognized are hydrogen, oxygen, nitrogen, and sulfur; the reactive halogens fluorine, chlorine, bromine, and iodine; and the noble gases helium, neon, argon, krypton, xenon, and radon (see e.g. Larrañaga et al)

Suggest replacing "reactive" with "highly reactive" (in order to distinguish them from H, O, N and S. Sandbh (talk) 02:33, 3 October 2022 (UTC)

---

Before:
Vernon had earlier reported that these three elements were instead sometimes counted as metalloids.

After:
Vernon had earlier reported that these three elements were counted as metalloids.

Suggest this ce be reverted since the before version is accurate whereas the after version is not. Sandbh (talk) 02:40, 3 October 2022 (UTC)

---

Line 86

Before:
Outwardly, about half of nonmetallic elements are colored or colorless gases; most of the rest are shiny solids. Bromine, the only liquid, is so volatile that it is usually topped by a layer of its fumes; sulfur is the only colored solid nonmetal.

After:
About half of nonmetallic elements are gases; most of the rest are shiny solids. Bromine, the only liquid, is so volatile that it is usually topped by a layer of its fumes; sulfur is the only colored solid nonmetal.

Suggest this ce be reverted given the reference to S being colored. Sandbh (talk) 02:48, 3 October 2022 (UTC)

Surely this needs some sort of disclaimer about allotropy, given phosphorus. Double sharp (talk) 22:37, 9 October 2022 (UTC)

I think a hatnote would address this: "Physical properties apply to elements in their most stable forms in ambient conditions." Sandbh (talk) 01:57, 11 October 2022 (UTC)

---

The remaining copy edits are right on target. Sandbh (talk) 02:50, 3 October 2022 (UTC)

Proposed edits

I propose to change this...

Definition and applicable elements

A nonmetal is a chemical element that has low density and moderate to high electronegativity. They also lack metallic attributes such as luster, deformability, good thermal and electrical conductivity, and low electronegativity.[11] Since there is no rigorous definition of a nonmetal,[10][12][13] some variation exists among sources as to which elements are classified as such. The decisions involved depend on which property or properties are regarded as most indicative of nonmetallic or metallic character.[14]

...to this:

Definition and applicable elements

A nonmetal is a chemical element deemed to lack a preponderance of metallic properties such as luster, deformability, good thermal and electrical conductivity, and the capacity to form a basic (rather than acidic) oxide.[11] Since there is no rigorous definition of a nonmetal,[10][12][13] some variation exists among sources as to which elements are classified as such. The decisions involved depend on which properties are regarded as most indicative of metallic or nonmetallic character.[14]

The "after" version is less prescriptive and more in keeping with the literature, which tends to focus on what nonmetals aren't rather that what they are. It also removes the reference to electronegativity. I cannot see any easy alternative place in the article for the accompanying density v EN image, so it seems like it'll have to go, at least for now.

@John: I suspect this proposal may go a long way to resolving your concerns. How does it look to you? Sandbh (talk) 05:28, 13 October 2022 (UTC)

As the lede (including 1st sentence) is based upon/derived from the article body, the bodytext as discussed in § Copyedit (16:52) § Color and state of matter should be resolved first. Otherwise, this is breaking good (encyclopedic) logic; it is not a textual issue. To be clear: as long as lede and abody do not match in this sense, I oppose this incidental edit. Also, it is useless to push this change in as a matter of John's language quest. btw, I think ";" should be ",". DePiep (talk) 06:33, 13 October 2022 (UTC)

The first sentence of the lede says:

"A nonmetal is a chemical element that lacks a predominance of metallic properties; they range from colorless gases (like hydrogen) to shiny and high-melting point solids (like boron)."

The latter part, which I wrote with the general reader in mind, is derived from later in the article where it says:

General properties

Physical

About half of nonmetallic elements are gases; most of the rest are shiny solids. Bromine, the only liquid, is so volatile that it is usually topped by a layer of its fumes; sulfur is the only colored solid nonmetal...Nonmetals that form giant structures...(e.g. silicon), have higher melting and boiling points, as it takes more energy to overcome their stronger covalent bonds, so they are all solids.

The accompanying image shows the variety in form and colour of the nonmetals.

John noted that his copyediting needs to remain true to the sources. My proposed incidental edit is designed to facilitate this.

Thanks for the suggestion; I've replaced the ; with commas. Sandbh (talk) 05:25, 14 October 2022 (UTC)

Color and state of matter

DePiep raises an interesting point.

Obviously all metals are shiny and all bar Hg are solid. I know a little about the shininess; visible light gets scattered by the delocalised surface electrons.

The nonmetals are shiny (B, Si, Ge, As, Sb, Te; C, black P, Se, I), colored (S, F, Cl, Br) or colorless (H, N, O, and the noble gases).

The mechanism of shininess for the semimetals C, As and Sb is the same as that for the metals.

The mechanism for the rest of the shiny nonmetals, which are all semiconductors, arises from their band gaps being less than equal to the visible spectrum cut off of 1.8 eV. S has a bigger band gap, giving rise to its yellow color.

The mechanism for the remaining colored and colorless nonmetals, has to do with the permitted energy levels that their individual electrons occupy.

Why metals are nearly all solid whereas nonmetals cover all three bases is something I'll need to look further into. I do know that Hg is liquid on account of relativistic effects.

Par for the course, there is a little bit of overlap going on here in that C, As, Sb have the electronic structure of semimetals, as does Bi. Yet the chemistry of C, As, Sb is largely nonmetallic whereas Bi is regarded as having just enough metallic character to merit being admitted to the metal club. Frex, nitric acid gives carbon dioxide with C, arsenic acid with As, antimony trioxide with Sb, and bismuth nitrate with Bi.

I intend doing this work as a stand alone exercise from John's copyediting, and will post the results here. Sandbh (talk) 05:18, 2 October 2022 (UTC)

TL;DR. If this is the missing encyclopedic link, it should be in the article. Then, I don't think it has the right proportions. As talkpage post, it doesn't solve the question. DePiep (talk) 06:50, 7 October 2022 (UTC)

Well in my favourite counterexample to that, sulfuric acid already gives the sulfate with Sb as well as Bi (but not As). To some extent it can be national-traditional variation: from what I remember, Russian authors are likelier to call Sb a metal than English authors (though this may be because Russian authors often don't recognise a "metalloid" category).

Metals are nearly all solid because the metallic bond is strong and, crucially, extends over the whole network. You really need special circumstances to have a liquid metal: few electrons to share (Rb, Cs, Fr), relativistic pseudo-closed shell configurations (Hg, maybe Cn and Fl), or some weird molecular-like thing going on (Ga). (And here I am assuming 40°C weather to define "liquid".) When the covalent bonds extend over the whole network, we always get a solid, too (B, C, black P, Si, Ge, Se, Te), and sometimes we even get one where it doesn't when van der Waals forces are strong enough (the big ones: white P, S, yellow As, red Se, I). So it's not a metal vs nonmetal thing; it's closer to a giant-structure vs molecular thing (blurring as the molecule gets heavier). Double sharp (talk) 22:36, 9 October 2022 (UTC)

Antimony does not really give a sulfate. Solid antimony sulfate contains infinite ladders of SO₄ tetrahedra and SbO₃ pyramids sharing corners. It is often described as a mixed oxide, Sb₂O₃.3SO₃. Sandbh (talk) 03:00, 11 October 2022 (UTC)

If this is your objection to Double sharp's post, that means the rest is a good replacement for the color & phase topic in the article, starters. IOW, this is the encyclopedic approach (some ce todo allright). It also leads to the conclusion that it is not 1st-sentence-worthy. DePiep (talk) 08:19, 12 October 2022 (UTC)

This is a bad draft of the colour paragraph:

"Nonmetallic elements are either shiny, colored, or colorless. For graphitic carbon, black phosphorus, arsenic, antimony, selenium and iodine their structures feature varying degrees of delocalised electrons that scatter incoming visible light, resulting in a shiny appearance (Wiberg 2001, p. 416). The colored nonmetals (sulfur, fluorine, chlorine, bromine) absorb some colours (wavelengths) and transmit the complementary colours. For chlorine, its "familiar yellow-green colour...is due to a broad region of absorption in the violet and blue regions of the spectrum" (Elliot 1929, p. 629).^ For the colorless nonmetals (hydrogen, nitrogen, oxygen, and the noble gases) their electrons are held sufficiently strongly such that no absorption occurs in the visible region of the spectrum, and all visible light is transmitted.”

^ The absorbed light may be converted to heat or re-emitted in all directions so that the emission spectrum is thousands of times weaker than the incident light radiation.

•  Elliot A 1929, "The absorption band spectrum of chlorine", Proceedings of the Royal Society A, vol. 123, no. 792, pp. 629–644
•  Wiberg N 2001, Inorganic Chemistry, Academic Press, San Diego. Wiberg is here referring specifically to iodine.

The difference in solid, liquid or gaseous forms of nonmetals is addressed in the Physical properties section, i.e. "The internal structures and bonding arrangements of the nonmetals explain their differences in form...".

— Sandbh (talk) 06:45, 21 October 2022 (UTC)

@Double sharp: I've added a paragraph to the Physical section on the colours of nonmetallic elements. Could you please check to see if that looks OK? (The accompanying footnote needs a citation but the rest should be OK.) Thank you, Sandbh (talk) 12:33, 23 October 2022 (UTC)

It looks pretty much alright to me, based on what I could find in the literature. Double sharp (talk) 19:42, 29 October 2022 (UTC)

RfC on the Classification of elements

Over at WT:ELEMENTS an RfC is opened on the topic highly relevant on the nonmetals too. See § Request for comment on the classification of chemical elements. You are invited to participate. DePiep (talk) 07:23, 17 February 2023 (UTC)

Astatine

Isn't astatine a metalloid? Here it says astatine is a metal, but most other sources say it's a metalloid or nonmetal? 2603:6000:8740:54B1:21BE:C597:B635:6023 (talk) 17:33, 26 February 2023 (UTC)

In lists of metalloids, astatine appears about 40% of the time.

The bulk properties of astatine remain unknown as a visible quantity of it would immediately self-vaporize from the heat generated by its radioactivity. It remains to be seen if, with sufficient cooling, a macroscopic quantity could be deposited as a thin film. Historically, "since elements in heavier periods often resemble their n+1 and n−1 neighbours more than their lighter congeners, astatine…was expected to be radioactive and metallic like polonium."[1]

Qualitative and quantitative assessments of its status, including having regard to relativistic effects, have been consistent with it being a metal:

1940. Astatine was judged to be a metal when it was first synthesized.[2] That assessment was consistent with some metallic character seen in iodine,[3] its lighter halogen congener.

1972. Batsanov calculated astatine would have a band gap of 0.7 eV[4] (but see the 2013 entry)

1983. Edwards and Sienko speculated that, on the basis of the non-relativistic Goldhammer-Herzfeld criterion for metallicity, astatine was probably a metalloid.[5] As the ratio is based on classical arguments[6] it does not accommodate the finding that polonium (cf. 2006 entry following) adopts a metallic (rather than covalent) crystalline structure, on relativistic grounds.[7] Even so it offers a first order rationalization for the occurrence of metallic character amongst the elements.[8]

2002. Siekierski and Burgess presumed astatine would be a metal in the context of some of the properties of iodine.[9]

2006. Restrepo et al., on the basis of a comparative study of 128 known and interpolated physiochemical, geochemical and chemical properties of 72 of the elements, reported that astatine appeared to share more in common with polonium (a metal) than it did with the established halogens and that, “At should not be considered as a halogen."[10] In so doing they echoed the 1940 observation that, "The chemical properties of the unknown substance are very close to those of polonium."[11]

2010. Thornton and Burdette observed that "Since elements in heavier periods often resemble their n+1 and n-1 neighbours more than their lighter congeners, eka-iodine [astatine]...was expected to be radioactive and metallic like polonium." [12]

2013. Hermann, Hoffmann, and Ashcroft predicted At would be an fcc metal, once all relativistic effects are taken into account, and that it would have a band gap of 0.68 eV (cf. Batsanov) if only some of these effects were taken into account.[13]

While astatine could reasonably be presumed to be a metalloid based on ordinary periodic trends, relativistic effects—as seen in gold, mercury, and the heavier p-block elements—are expected to result in condensed astatine being a ductile FCC metal. It could also be expected to show significant nonmetallic character, as is normally the case for metals in, or in the vicinity of, the p-block.

The suggested distinguishing criteria for metals and nonmetals place At in a metal quadrant.

References

1. Thornton BF & Burdette SC 2010, “Finding eka-iodine: Discovery priority in modern times”, Bulletin for the History of Chemistry, vol. 25, no. 2, pp. 86−96

2. Vasáros L & Berei K 1985, General properties of astatine, in Kugler HK & Keller C (eds), Gmelin Handbook of Inorganic and Organometallic chemistry, 8th ed., At, Astatine, system no. 8a, Springer-Verlag, pp. 107–28 (109)

3. Moody B 1991, Comparative Inorganic Chemistry, 3rd ed., Edward Arnold, London, p. 303

4. Batsanov SS 1971, Quantitative characteristics of bond metallicity in crystals, Journal of Structural Chemistry, vol. 12, no. 5, pp. 809–813 (811).

5. Edwards PP & Sienko MJ 1983, On the occurrence of metallic character in the Periodic Table of the Elements, Journal of Chemical Education, vol. 60, no. 9, p. 692

6. Edwards PP 1999, Chemically engineering the metallic, insulating and supercon-ducting state of matter, in Seddon KR & Zaworotko M (eds), Crystal Engineering: The Design and Application of Functional Solids, Kluwer Academic, Dordrecht, p. 416

7. Encyclopedia of the Structure of Materials, Elsevier, Oxford, p. 142; Pyykkö P 2012, Relativistic effects in chemistry: More common than you thought, Annual Review of Physical Chemistry, vol. 63, p. 56

8. Edwards PP & Sienko MJ 1983, On the occurrence of metallic character in the Periodic Table of the Elements, Journal of Chemical Education, vol. 60, no. 9, p. 695

9. Siekierski S & Burgess J 2002, Concise Chemistry of the Elements, Horwood Press, Chichester, p. 122

10. Restrepo G, Llanos EJ & Mesa H, Topological space of the chemical elements and its properties, Journal of Mathematical Chemistry, vol. 39, p. 411

11. Corson DR, MacKenzie R & Segrè E 1940, Possible production of radioactive isotopes of element 85, Physical Review, vol. 57, p. 459

12. Thornton BF & Burdette SC 2010, Finding eka-iodine: Discovery priority in modern times, Bulletin for the History of Chemistry, vol. 35, no. 2, p. 86

13. Hermann A, Hoffmann R & Ashcroft NW 2013, Condensed Astatine: Monatomic and metallic, Physical Review Letters, vol. 111

— Preceding unsigned comment added by Sandbh (talk • contribs) 03:22, 25 April 2023 (UTC) — Preceding unsigned comment added by Dhtwiki (talk • contribs)

@Dhtwiki and Sandbh: To deconfuse. Currently this article makes this top level distinction: Metal-Nonmetal only. So, no major class Metalloids in there. The Metalloids appear as subdivision of class Nonmetals. The article is rewritten this way by Sandbh, with the pre-overhaul GA-icon kept undiscussed.

So the OP Isn't astatine a metalloid? (i.e., not a Metal), in this class scheme requires redefinition of At as a Nonmetal first before it can be subclassified Metalloid. Recent complication: same author (Sandbh) appears to have changed the article object (ie, everything) as "chemically" only [1] while not changing anything to article body, title, TOC or setup???. This is disputable, in various ways, and is disputed. DePiep (talk) 08:41, 25 April 2023 (UTC)

Thank you DePiep.

Yes, the two great classes are (i) metals and (ii) nonmetals. This is a universal distinction. "Metalloids" is only a sometimes classification.

The treatment of elements occupying the frontier territory where the metals meet the nonmetals varies from author to author. Some consider them separate from both metals and nonmetals (and refer to them as metalloids); some regard them as nonmetals or as a sub-class of nonmetals. Other authors count some of them as metals, for example arsenic and antimony, due to their similarities to heavy metals. It has been known for over 100 years that the elements commonly recognised as metalloids (B, Si, Ge, As, Sb, Te) behave chemically like nonmetals. The article treats them as "metalloid nonmetals" in light of their chemical behavior, and for comparative purposes. The metalloids further meet the criteria for nonmetals of low density and relatively high electronegativity.

Astatine has at various times been counted as a metal, metalloid, or nonmetal.

It isn't included in the article since it has been counted as a (post-transition) metal. The article says:

"Astatine, the fifth halogen, is often ignored on account of its rarity and intense radioactivity;[17] theory and experimental evidence suggest it is a metal."[18]

The edit in question changed the opening sentence from:

"In chemistry, a nonmetal (or non-metal) is a chemical element..."

TO

"A nonmetal (or non-metal) is a chemical element..."

There was no change to the article object, since nonmetals are still referred to in terms of physical and chemical properties. Sandbh (talk) 06:39, 27 April 2023 (UTC)

Article could be revised and renamed: Main Group Chemistry

The article is nice, although the topic called Main Group chemistry might be more appropriate. Has that idea been discussed? --Smokefoot (talk) 22:25, 11 April 2023 (UTC)

Ealier discussion: WT:CHEM § Nonmetal: Help with copyediting?. Could be that Main Group is a valid topic, but I do not see how it would be an alternative for this topic. That is, replacing nonmetal chemistry. (Incidentally, does it differ from main group?) DePiep (talk) 06:29, 12 April 2023 (UTC)

Good point. You are correct: Nonmetal is a thing. The article is essential. But the chemistry stuff (reactions, structures, minerals) should mostl be in Main Group Chemistry.

Yes, I realize that I am discussing this issue in two places, but I dont think that anyone at the Chem Project cares.--Smokefoot (talk) 20:08, 12 April 2023 (UTC)

No problem, Smokefoot, I only added the link to keep the arguments, already made, at hand. I assume this talkpage is best place. DePiep (talk) 06:19, 13 April 2023 (UTC)

Hatnote "In chemistry"

Added hatnoting "This article is about nonmetal elements in chemistry" [2] is confusing, sloppy and not correct.

For starters, the body and the TOC say otherwise (eg "Physics"); this distinction is not made. Further hatnote specs (astronomy, metallicity, nonmetallic substances, in physics, valence and conduction bands) add to the confusion/mistake. If article content is changed into this, the article should be moved. But morte likely this is inappropriate application of {{hatnote}}; more like trying to fit topic description (lede issue) in a WP:HATNOTE.

I request and expect Sandbh starts a talk on this page proposing all desired changes coherently. DePiep (talk) 06:27, 24 April 2023 (UTC)

Thanks DePiep for your interest. I followed WP:HAT in adding the hatnote.

The only other mention of "physics" is in the Discovery section of the main body of the article, which says:

"Chemistry- or physics-based techniques used in the isolation efforts were spectroscopy, fractional distillation, radiation detection, electrolysis, ore acidification, displacement reactions, combustion and heating; a few nonmetals occurred naturally as free elements."

This does not have anything do with the concept of a nonmetal in physics.

Astronomy and materials science are not mentioned in the main body.

--- Sandbh (talk) 07:14, 24 April 2023 (UTC)

Name change I'm inclined to change the name of the article to "Nonmetal (chemistry)" and to create disambiguation links for:

Nonmetal (astronomy) --> Metallicity

Nonmetal (physics) --> Valence and conduction bands

The hatnote would be reduced to "For nonmetallic substances see Materials science."

Sandbh (talk) 01:13, 28 April 2023 (UTC)

I've renamed the article to Nonmetal (chemistry) and trimmed the hatnote, after setting up redirects for Nonmetal (astronomy) and Nonmetal (physics). --- Sandbh (talk) 07:26, 30 April 2023 (UTC)

Nonmetal halogen, halogen nonmetal

Both terms are found in the literature.

Since there are alkali metals, alkaline earth metals, and transition metals, i.e. the convention is to put "metals" last, I've replaced mentions of "nonmetal halogens" with "halogen nonmetals". --- Sandbh (talk) 08:24, 24 April 2023 (UTC)

First paragraph of lede

The first paragraph of the lede starts by explaining what nonmetals are not:

"A nonmetal (or non-metal) is a chemical element that generally lacks a predominance of metallic properties; they range from colorless gases (like hydrogen) to shiny solids (like carbon, as graphite). They are usually poor conductors of heat and electricity, and brittle or crumbly when solid, due to their electrons having low mobility. In contrast, metals are good conductors and most are easily flattened into sheets and drawn into wires since their electrons are generally free-moving. Nonmetal atoms tend to attract electrons in chemical reactions and to form acidic compounds."

I am thinking about changing this so that nonmetals are instead explained in terms of what they are:

"A nonmetal is a type of chemical element that is a poor electrical conductor or is a mechanically weak and brittle solid the most stable oxide of which is acidic. They range from colorless gases (like hydrogen) to shiny substances (like carbon, as graphite). Their electrons have low mobility. In contrast, metals are good conductors and most are easily flattened into sheets and drawn into wires since their electrons are generally free-moving. Nonmetal atoms tend to attract electrons in chemical reactions and and to form acidic compounds."

The reference to poor electrical conductivity applies to nearly all nonmetals. Carbon, as graphite, is an exception. But it is a mechanically weak and brittle substance, and CO₂ is an acidic oxide.

Among the metals, and semimetals (in a physics-based sense), gallium, arsenic, antimony and bismuth are brittle and mechanically weak. Gallium trioxide is amphoteric; aqueous solutions of arsenic trioxide are weakly acidic; antimony trioxide is amphoteric, but has acidic properties predominating; and bismuth trioxide is basic.

--- Sandbh (talk) 02:23, 28 April 2023 (UTC)

Well, how do the sources typically define things?

It seems to me that nonmetallicity is more correlated with keeping one's own electrons than attracting others', i.e. electronegativity rather than electron affinity. The noble gases are a clear example. Also, Cs has a higher electron affinity than B. Electronegativity is also not perfect considering that Au beats Si by this measure, but at least it doesn't have literally alkali metals beating nonmetals, but the noble metals. Double sharp (talk) 10:41, 28 April 2023 (UTC)

The sources are about 50:50 between defining nonmetals as (i) elements either not having the properties of a metal or (ii) in terms of more specific properties as per following 20 examples from the literature:

1. …a substance that conducts heat and electricity poorly, is brittle or waxy or gaseous, and cannot be hammered into sheets or drawn into wire. Nonmetals gain electrons easily to form anions.
2. A nonmetal is an element whose atoms tend to gain (or share) electrons.
3. A nonmetal is a chemical element that is mechanically weak in its most stable form, brittle if solid, and usually gains or shares electrons in chemical reactions.
4. As a result of the free electron, graphite, though a nonmetal, is able to conduct electricity while diamond cannot. 
5. The distinctive chemical property of a nonmetal is the ability to gain electrons to form an anion when reacting with a metal. The nonmetals have large ionization energies and most have negative electron affinities.
6. If the oxide of a nonmetal is placed in water, the mixture will be acid.
7. The simplest way to tell a metal from a nonmetal is that most nonmetals do not conduct thermal energy or electricity. 
8. nonmetals are insulators, with a few rare exceptions.
9. A nonmetal is an element that gains or shares electrons when it combines chemically. There is no set of physical properties that applies to all nonmetals, there is for the metals.
10. A metal is a lustrous malleable element that is a good conductor of heat and electricity; a nonmetal is an element that is a poor conductor. 
11. A nonmetal is an element that tends to gain valence electrons in chemical reactions, becoming an anion in the process.
12. Chemically, the property of an element that makes it a nonmetal is the element's ability to gain electrons. 
13. A nonmetal is an element that usually has a low density, a low melting point, and is a poor conductor of heat and electricity.
14. A nonmetal is an element that is relatively easily reduced.
15. A nonmetal is a kind of matter that does not have a metallic luster, is a poor conductor of heat and electricity, and when solid, is a brittle material that cannot be pounded or pulled into new shapes.
16. A nonmetal is one of a number of elements, including gases, liquids and solids, which are grouped together because they do not conduct heat or electricity well, are not ductile and malleable, and do not reflect light well. Chemically, nonmetal atoms form negative ions.
17. Bands in metals In terms of the band theory, the distinction between a metal and a non-metal is that in the former there are incompletely filled bands.
18. the principal chemical property of a non-metal is its ability to form a negatively charged anion by accepting electrons from a metal.
19. A non-metal is an element which ionizes by electron gain.
20. A non-metal is an element that has four or more valence electrons.

The properties include poor conductivity; brittle and mechanically weak if solid; usually low density and mp; large ionization energy; gain or share electrons; usually negative EA; form negative ions; acidic oxides. --- Sandbh (talk) 02:54, 29 April 2023 (UTC)

I've updated the lede paragraph to refer to what nonmetals are, rather than what they are not. Sandbh (talk) 07:22, 30 April 2023 (UTC)

---

I found a hybrid nonmetal entry by Read J 1965, in JR Newman (ed.), The International Encyclopedia of Science, Thomas Nelson and Sons, London, p. 832:

"NONMETALS stand apart from METALS in many ways, both physically and chemically, although these two classes of elements merge into one another. Physically, nonmetals do not exhibit luster or polish; they are poor conductors of heat and electricity; if solid, they are often brittle, they are not ductile, and they possess poor tensile strength. At ordinary temperatures some are solid, some liquid, and some gaseous: their melting points range from −272°C(−457.6°F), under 26 atm pressure, for helium, to above 3550°C (6422°F) for carbon. Their values for specific gravity are low, compared with those for metals. Chemically, their oxides usually react with water to form acids, and their chlorides are often decomposed by water."

It is a good effort but not without errors.

That "nonmetals do not exhibit luster or polish" is contradicted by graphitic C, black P, gray Se, and I. That they are, "if solid...often brittle" is not quite true since all solid nonmetals are brittle, unless he had white P in mind which can be cut with a knife however black P, which is brittle, is the most stable form. That they are "poor conductors of heat and electricity" is contradicted by graphitic C. While Read says that "some" are liquid, bromine is the only liquid nonmetal.

--- Sandbh (talk) 02:39, 1 May 2023 (UTC)

---

I restored the lede paragraph back to saying what nonmetals aren't since there is no agreement as to what they are. Sandbh (talk) 07:49, 1 May 2023 (UTC)

Perhaps you could say "Nonmetal is a classification of elements. It commonly refers either to <foo> or <fab>"? If there is more than one common definition of nonmetal, mentioning all of them would be better than implying there is only one accepted definition. Jo-Jo Eumerus (talk) 09:58, 1 May 2023 (UTC)

Simplifying the lede

I've adjusted the lede paragraph, and made associated edits later in the article, to make things easier to follow in terms of what is a nonmetal in the broadest sense of the term.

While there is no common rigorous definition of a nonmetal in terms of the precise properties involved, a broad definition based on relatively low density (a physical property) and relatively high electronegativity (chemical) encompasses:

• the 23 elements within the scope of the article; and therefore
• the other varying conceptions of nonmetals and the resulting sets of of nonmetallic elements

Mention of the relatively low density and relatively high EN of nonmetals is set out in Hein M & Arena S 2013, Foundations of College Chemistry, 14th ed., John Wiley & Sons, pp. 226, G-6.

Here are extracts from a dozen sources corroborating the low density of nonmetals (#2 also refers to high EN):

1. A nonmetal is an element that usually has a low density
2. Unlike metals, solid non-metals are dull, brittle and not malleable. They also tend to be less dense than metals, and have lower melting and boiling points (apart from carbon). With high electronegativity (see here) non-metal elements ...
3. Nonmetals include gases , liquids , and solids . They are generally dull instead of shiny , and they do not conduct heat or electricity very well . They cannot be shaped into wires or thin sheets , and they tend to have a low density .
4. Nonmetals have a low density .
5. Nonmetals are characterized by lack of luster , lack of conductivity , brittleness , and low density .
6. Nonmetals appear on the right side of the periodic table a . These elements usually have a low density
7. Dull , reflecting light poorly or absorbing strongly Low density
8. Have low density
9. Nonmetals are usually lighter in weight than metals ,
10. Non- metals are generally lighter in weight than metals
11. Non - metals are usually lighter than metals
12. Most nonmetals have no luster , are soft , are poor conductors , and have a low density.

And a dozen referring to high(er) electronegativity:

1. With high electronegativity (see here) non-metal elements ..
2. Table 11.5 shows that the relative electronegativity of the nonmetals is high and that of the metals is low.
3. The Allred Rochow electronegativities of the nonmetals are larger than 1.8, those of the metals are smaller than 1.5
4. Metals, in the lower left corner of the table, have low electronegativities and nonmetals, in the upper right 
5. These two trends result in nonmetals generally having higher electronegativities than metals
6. The electronegativities of metals are small while those of nonmetals are large. These data are useful in the classification of metals from non-metals 
7. Elements with high electronegativity (such as nonmetals) have a greater ability to attract electrons
8. Metals are the least electronegative elements (they are electropositive) and nonmetals the most electronegative.
9. Some of the elements have high values of electronegativity and some have lower values. Those with low electronegativity values are called metals and those with high electronegativity values are categorized as nonmetals
10. Nonmetals are much more electronegative than metal.
11. The most electronegative elements are the nonmetals on the far right of the periodic table 
12. Nonmetals have high electronegativities.

--- Sandbh (talk) 07:04, 24 May 2023 (UTC)

List of miscellaneous items

So, taking a dive in this article, specifically this version:

• "largely make up the" I know this is shortest, but would "make up most of the" be a bit sounder grammatically? Done
• "namely boron; silicon and germanium; arsenic and antimony; and tellurium" might work better as a parenthetical. Done
• Footnote 6 I think "both metals" is better than "metals both" Done
• I know, hypocritical from me but the "Physical" section could benefit from less instances of "occurs" Done
• "as used in non-stick coatings for pans and other cookware." is unreferenced. Done
• "From right to left in periodic table terms, three or four kinds of nonmetals are more or less commonly discerned. These are: the relatively inert noble gases;" are also unreferenced. Done
• "Metalloids are here treated as nonmetals in light of their chemical behavior, and for comparative purposes." is unreferenced. Done
• "In 2014 it was reported that the Earth's core" sounds a bit like a WP:PROSELINE thing; can it be reworded to be less time-dependent? Done
• "Dingle explains the situation this way:" who is this Dingle? Done
• "Oxygen is found in the atmosphere; in the oceans as a component of water; and in the crust as oxide minerals." lacks a reference. Done
• I don't think that having a "daily cost" item is a good idea. I doubt that such prices are stable enough that they could be kept up-to-date with reasonable effort.

I rechecked the costs as at April 2023 since I did this originally as at August 2022. In the ensuing eight months there was hardly any variation, in relative terms. I suspect that an annual check would suffice, an idea I got from you. Sandbh (talk) 08:20, 3 May 2023 (UTC)

• "Chemistry- or physics-based techniques used in the isolation efforts were spectroscopy, fractional distillation, radiation detection, electrolysis, ore acidification, displacement reactions, combustion, and heating; a few nonmetals occurred naturally as free elements." lacks a reference. Done
• "Physical properties apply to elements in their most stable forms under ambient conditions, and are listed in loose order of ease of determination. Chemical properties are listed from general to descriptive, and then to specific. The dashed line around the metalloids denotes that, depending on the author, the elements involved may or may not be recognized as a distinct class or subclass of elements. Metals are included as a reference point." lacks a reference. Done
• What is the source for the ionization energies in the comparison table? Done
• Footnotes 4, 12, 13, 26 need a source Not applicable

Note 4 does not need a cite since it is only listing the grayed-out elements in the parent image; ditto note 12 sets out the first row elements in the parent image; note 13 as per note 4; note 26 is a meta-explanation of what is going on in the sentence.

• Footnote 14 lacks a reference for one sentence Not applicable

That is an introductory and explanatory sentence; the cites are in the following three sentences/paras.

• Footnote 23 has the somewhat mysterious "combined with sulfur" Done

I can do a source spot-check if so desired. Jo-Jo Eumerus (talk) 09:30, 2 May 2023 (UTC)

Tx JJ for this impressive list. I count 17 items, nine of which are for missing references. More refs should be no problem. The remaining eight items should be OK to address.

A source spot check was completed in one of the more recent FAC nominations by, as I recall, Complex rational.

--- Sandbh (talk) 07:35, 3 May 2023 (UTC)

All items have now been addressed. Sandbh (talk) 13:32, 3 May 2023 (UTC)

Merge or split?

It seems that it would be much better if either the history section is split and merged with Discovery of the nonmetals, or the opposite, merge the discovery article here. It is short enough to go both ways. ReyHahn (talk) 14:12, 26 July 2023 (UTC)

Astatine and Polonium

Isn't astatine a metalloid (sometimes considered) ? I've even seen polonium considered a metalloid. 2603:6000:8740:54B1:98C0:1879:4C99:365D (talk) 02:08, 30 August 2023 (UTC)

Both have been classified as metalloids by some authors, though the consensus isn't as clear as for the main ones (B, Si, Ge, As, Sb, Te). See lists of metalloids for a more in-depth analysis. ^Complex/_Rational 11:15, 30 August 2023 (UTC)

Thanks. I've usually seen astatine regarded as a nonmetal or metalloid; occasionally as a metal. Polonium I've seen regarded as a metalloid, though usually a metal. 2600:1008:B18F:94F7:495F:FB73:818D:885A (talk) 17:53, 31 August 2023 (UTC)

Astatine has an unusual history in that when it was first syntheized it was considered to be a metal. Experimental evidence and recent theory suggests it may indeed be a metal. In-between it seems to have suffered from its association with the halogens. Ergo it must be a nonmetal, ignoring trends of increased metallicity going down the group. Non-relativitic calcuations pointed to it being a semiconductor and hence a metalloid candidate. Relativity points to it being a post-transition metal.

Polonium is soluble in acids, forming the rose-coloured Po2+ cation and displacing hydrogen: Po + 2 H+ → Po2+ + H2. It has no band gap and no semiconducting allotropes. Hence it's a metal. Sandbh (talk) 05:46, 19 September 2023 (UTC)

Polonium is further down in the electrochemical series than hydrogen, and appears in about the same place as ruthenium. Hence, a caveat must be added: polonium often gets oxidised by media that electrochemically should not oxidise it, because of radiolytic decay products. Double sharp (talk) 15:37, 12 January 2024 (UTC)

Outstanding items from FAC7 nomination

@Graham Beards, YBG, and Double sharp: Please see below. @Michael D. Turnbull, Mirokado, and Jo-Jo Eumerus: fyi.

I understand that the following items had still to be checked off:

A small mention of metalloid outliers (Double sharp)

"If you like, there may be room for an "Outliers" sub-sub-section at the end of the Metalloids section. This could address Po, Al, C, Bi, Be, Sn, Ga and Pb, all of which have been identified as metalloids in at least one source, per the Lists of metalloids article".

@Double sharp: Done. I've added such a (condensed) section. --- Sandbh (talk) 06:35, 24 October 2023 (UTC)

@Sandbh: Thanks, I like it. I feel it nicely illustrates the continuum between metals and nonmetals. Double sharp (talk) 08:56, 24 October 2023 (UTC)

Complementary pairs (YBG)

Please see the new section about this, hereunder.

More tendency speak (Double sharp)

"@Double sharp: I suspect there is agreement between the sources in the sense that they all draw on (prioritise?) a few or several properties from the same big set of all properties associated with nonmetals. There are of course differences in just which few or several properties each author chooses. Does the question then become which few properties can do a reasonable job of more or less encompassing the big set? --- Sandbh (talk) 04:05, 22 October 2023 (UTC)[reply]

@Sandbh: I don't think we should be the ones making that decision. I think we should rather give the list, which is mostly agreed on (modulo what exactly people make of metalloids), and then mention tendencies that people have used as criteria. Double sharp (talk) 04:07, 22 October 2023 (UTC)[reply]

@Double sharp: OK; if you feel there's a need for more tendency-speak in the article, that should be doable. --- Sandbh (talk) 04:26, 22 October 2023 (UTC)"

An extraction periodic table (YBG)

"This would be a fun place to insert another PT extract, with five colors (for the five sources) and two shadings (solid for exclusively, striped for mainly)"

@YBG: Done: Thanks; I've now added such an extract. --- Sandbh (talk) 04:03, 27 October 2023 (UTC)

Double up (Graeme Beards)

"It some instances it's getting worse. See this in the Lead for example: "There is no universally agreed definition of the term... there is no universally accepted definition of a nonmetal". How many times do the readers need to be told?"

Done. This has been fixed. Sandbh (talk) 07:11, 23 October 2023 (UTC)

--- Sandbh (talk) 23:37, 22 October 2023 (UTC)

@Double sharp, @Graham Beards: I believe everything in this section has been resolved, but I hesitate to collapse it as it contains issues you folks raised, not me. I do expect we would benefit from another read through to reduce or eliminate tendency speak, but that, imho is a project for another day and another section. YBG (talk) 05:50, 29 November 2023 (UTC)

@Double sharp/Sandbh/Graham Beards There’s been nothing new said in over a month; I’ll wait another week and mark this section resolved. YBG (talk) 03:41, 7 January 2024 (UTC)

Complementary pairs (follow-on from previous section)

resolved YBG (talk) 05:40, 29 November 2023 (UTC) Continued in Pairs again. YBG (talk) 01:06, 17 December 2023 (UTC)

My biggest concern [about the Nonmetal article] is related to the pairing of nonmetal classes with a “complementing” set of metals. The pairing of nonmetal classes and metal classes is a beautiful and symmetric, but I suspect it is a bit fringe to be so prominently displayed in this article. There are RS listed in the pictures that presumably show that a given author compared a specific nonmetal category with a specific metal category. But the sources are different for each one. Let me draw a comparison. In Classical Planet § Alchemy we see a list of planets and corresponding metals. The entire set of pairings is well attested in RS. But what if I only found one RS that compared the Sun to gold, a different RS that compared the moon to silver, and a third that compared Mercury to mercury, and a fourth that compared Venus to copper, a fifth, Mars to iron, a sixth, Jupiter to tin, and a sixth, Saturn to lead? In this case, I believe it would be violate WP:SYNTH to prominently display the whole set of pairings as though it were some sort of organizing principal. The pairings of nonmetal categories with metal categories appears to be this same sort of synthesis, and so I say, no matter how beautiful and symmetrical this is, it does not belong in a WP article. I would be very interested to know what other reviewers think of this concern. YBG (talk) 06:22, 21 October 2023 (UTC) ping Graham Beards|Michael D. Turnbull|Jo-Jo Eumerus|Double sharp|Sandbh: Please consider commenting on this. I will consider this concern resolved if either (1) the nominator removes the info about complementary sets of metals, or (2) no other reviewer voices a concern about this, or (3) one other reviewer gives what they (not me) consider is a good reason that this is not a concern. YBG (talk) 13:37, 21 October 2023 (UTC) I agree with your concern. Not only is each comparison cited to a different source, but the last one (unclassified to transition) is straightforwardly SYNTH (see ref. 158; neither source quoted actually spells out the connexion). Double sharp (talk) 14:11, 21 October 2023 (UTC) ping Jo-Jo Eumerus|Double sharp|YBG: I've added a citation that mentions the four complementary sets. --- Sandbh (talk) 03:55, 22 October 2023 (UTC) WP:NOT says A Wikipedia article should not be a complete exposition of all possible details, but a summary of accepted knowledge regarding its subject. Verifiable and sourced statements should be treated with appropriate weight. (emphasis added) Citing your own article suggests that someone as well read as you could find no other RS that organizes things this way, which seems to prove my point: this is a novel idea not yet ready for WP. I suggest that it is best to leave it out for now. In a few years, if this organizing scheme is as useful as it is beautiful, other authors will pick it up and it can be included with no objection. YBG (talk) 04:28, 22 October 2023 (UTC) Thank you YBG. There is nothing "novel" in this. The background to the complementing sets is that the pairing of metals and nonmetals, and alkali metals and halogens, forms a foundational technique in chemistry education: ... we focus mainly on the gross structure – the metals are here, the non-metals are there, and so on. Once they have grasped this, you can start to show that there's some order to it. We talk about the Group 1 alkali metals and start to see that they're all similar in some way. Then at the other extreme there are the ...halogens. The idea that the table shows us how to group similar elements starts to come together in this way. Niki Kaiser (2019) Notre Dame High School, Norwich, UK There is a long history in the literature of complementing sets, for example: What, in general, is the difference between active metals, less active metals, less active non-metals, active non-metals, and inert gases…? --- Friedenberg EZ 1946, A Technique for Developing Courses in Physical Science Adapted to the Needs of Students at the Junior College Level, University of Chicago, Chicago, p. 230 For more recent references there are: Describe how groups of elements can be classified including highly reactive metals, less reactive metals, highly reactive nonmetals, less reactive nonmetals, and some almost completely nonreactive gases. --- Padilla MJ, Cyr M & Miaoulis I 2005, Science explorer (Indiana Grade 6), teachers's edition, Prentice Hall, Upper Saddle River, New Jersey, p. 27 Those [elements] classified as metallic range from the highly reactive sodium and barium to the noble metals, such as gold and platinum. The nonmetals…encompass the…the aggressive, highly-oxidizing fluorine and the unreactive gases such as helium. --- Weller et al. 2018, Inorganic Chemistry, 7th ed., Oxford University Press, Oxford, preface A similar pattern occurs along the periods: Across each period is a more or less steady transition from an active metal through less active metals and weakly active non- metals to highly active nonmetals and finally to an inert gas. --- Beiser A 1968, Perspectives of modern physics, McGraw-Hill, New York The pairing of the noble metals and gases is mentioned in no less a reputable source then Wiberg. The pairing of the post-transition metals and the metalloids occurs even in a popular science book by Adrian Dingle (2017) who has written extensively on PT matters: [With] no-doubt metals on the far left of the table, and no-doubt non-metals on the far right ... the gap between the two extremes is bridged first by the poor [post-transition] metals, and then by the metalloids—which, perhaps by the same token, might collectively be renamed the "poor non-metals". That just leaves the transition metals and the unclassified nonmetals, both of which are bridging in nature, as observed by Atkins, and Welcher. I won't fuss about this; if need be it'll be easy enough to revert the complementing sets. That said, could you please consider the following: The long history of the idea of parallels among the elements between e.g. active metals, less active metals, less active nonmetals and active nonmetals. The cited article was published in a reliable, peer reviewed journal. It's been cited seven times by other authors. Each complementing set has been cited in other reliable sources. An encyclopedia, as I understand the nature of WP, collects and presents what is understood to be factual information, as is the case here. --- Sandbh (talk) 13:08, 22 October 2023 (UTC) Well, I guess I wasn’t as clear as I could have been. I did not claim that the idea of pairing was novel, nor that the individual pairings were novel, but that the system as a whole is too novel to be prominently displayed. That others cite the article is interesting, but what I was looking for is some independent source that actually adopts this system. That was what I was hoping you could cite. If I were writing this (which I am not), I would remove all of the discussion about pairings. This is, after all, primarily an article about nonmetals and not an article comparing them to metals, nor is it primarily an article about the subcategories, and it is certainly not an article about comparing the nonmetal subcategories to metal subcategories. If I were determined to include something about this system of complementary subcategories (which I am not), I would add a single 2 sentence footnote somewhere in the introductory section about types. That is as far as I could go, but even that much seems undue to me. YBG (talk) 23:50, 22 October 2023 (UTC) Thanks YBG. I'll start by removing the image pairs. --- Sandbh (talk) 06:04, 23 October 2023 (UTC) @YBG: Could you kindly clarify what you meant by "the system as a whole ...[being] too novel to be prominently displayed"? At no time has the article displayed the system as a whole. Instead the parallels have been mentioned on a type by type basis. While this is an article about nonmetals, many nonmetallic elements are said to have some metallic aspects; and many metallic elements have some nonmetallic aspects. Hence the comparison with metals is relevant and fruitful. I've removed all the paired images except for the alkali metal-halogen image since this is Chemistry 101. Please note that the text for each of the four types of nonmetals includes a reference to geographic analogies, which I've listed hereunder for convenience: 1. "An analogy can be drawn between the noble gases and noble metals such as platinum and gold, as they share a similar reluctance to combine with other elements.[132] As a further analogy, xenon, in the +8 oxidation state, forms a pale yellow explosive oxide, XeO4, while osmium, another noble metal, forms a yellow, strongly oxidizing oxide,[133] OsO4. Additionally, there are parallels in the formulas of the oxyfluorides: XeO2F4 and OsO2F4, and XeO3F2 and OsO3F2.[134]" 2. "The highly nonmetallic halogens in group 17 find their counterparts in the highly reactive alkali metals, such as sodium and potassium, in group 1.[149] Further, and much like the halogen nonmetals, most of the alkali metals are known to form –1 anions, a characteristic seldom observed among metals.[150]" 3. "In the periodic table, to the left of the weakly nonmetallic metalloids are an indeterminate set of weakly metallic metals including tin, lead and bismuth,[153] sometimes referred to as post-transition metals.[154] Dingle explains the situation this way: ... with "no-doubt" metals on the far left of the table, and no-doubt non-metals on the far right ... the gap between the two extremes is bridged first by the poor (post-transition) metals, and then by the metalloids—which, perhaps by the same token, might collectively be renamed the "poor non-metals".[155]" 4. "There is a geographic analogy between the unclassified nonmetals and transition metals. The unclassified nonmetals are positioned between the strongly nonmetallic halogens on the right and the weakly nonmetallic metalloids on the left. Similarly, the transition metals occupy a region between the "virulent and violent" metals on the left side of the periodic table, and the "calm and contented" metals on the right. They effectively serve as a "transitional bridge" connecting these two regions.[184]" Could you please advise me if you have any concerns about any of these paragraphs? --- Sandbh (talk) 07:09, 23 October 2023 (UTC) I hope to get back to this later in the week. In the meantime perhaps @Double sharp would like to chime in. YBG (talk) 05:06, 24 October 2023 (UTC)

Pairs again

resolved YBG (talk) 05:38, 29 November 2023 (UTC)

@YBG: Earlier, you wrote: "There are RS listed in the pictures that presumably show that a given author compared a specific nonmetal category with a specific metal category. But the sources are different for each one." @Double sharp: Earlier you wrote: "I agree with your [YBG's] concern. Not only is each comparison cited to a different source, but the last one (unclassified to transition) is straightforwardly SYNTH (see ref. 158; neither source quoted actually spells out the connexion)." My understanding is that it does not matter that the sources "are different for each one." The whole article is an encyclopedic compilation drawing on multiple sources. No single source captures all of the information set out in the article. That said, the status of the image pairs is now that there are only two such pairs left: noble gas/noble metal; and halogen/alkali metal. For the noble gases/noble metals image and paragraph I've added three further cites, and copy-edited the topic sentence for the paragraph. For halogen/alkali metal, I earlier noted in this thread that I retained "the alkali metal-halogen image since this is Chemistry 101." For the unclassified/transition metals paragraph I've further copy edited this and it now relies on a single source, rather than two separate sources. Could your please review my responses to your concerns? All going well, I'm aiming to relist nonmetal on Monday Nov 6, my time. thanks, --- Sandbh (talk) 06:38, 26 October 2023 (UTC) @Sandbh: Thanks for the response and edits; I'm happy with this now. Double sharp (talk) 09:06, 26 October 2023 (UTC) I still find the comparisons overemphasized. Yes, people have made such comparisons. But they are too much in the weeds for an article summarizing the nonmetals. Furthermore, placing the paired picture at the top of the NG (or halogen) section makes it seem as though that comparison is one of the most important things about the NGs (or halogens), which it most certainly is not. YBG (talk) 00:14, 27 October 2023 (UTC)

More thoughts

The sub-sub sections below mostly relate to the paired comparisons. I’ve added some stuff to the first paragraphs of the group 17 and 18 sections. Feel free to copy edit and add refs. (Thanks for the wiki link, @ Sandbh!)

Resolved YBG (talk) 22:39, 5 November 2023 (UTC)
Another detail … looking at the section headings above, I see several that include “FAC”. If someone has the time, it would ge good to append a number (FAC7 or FAC6 or whatever) before the sections get archived. YBG (talk) 15:20, 27 October 2023 (UTC)

@YBG: Thanks for listing items of concern in an organised manner; @Double sharp: thanks for chiming in. --- Sandbh (talk) 05:34, 28 October 2023 (UTC)

Group 17/1 comparisons

resolved YBG (talk) 05:35, 29 November 2023 (UTC)

I think my recent addition to the 1st paragraph includes all that is needed about alkali metals. In keeping with the name halogen and the content of the first paragraph, I think a good illustration would have a picture with sodium metal on the left, chlorine gas on the right and a pile of table salt (or a salt shaker) in the center, with Na, NaCl, and Cl in the caption or even better in the pic itself. The most salient parts of the comparison paragraph have been incorporated into the first paragraph. The only significant fact not in that paragraph is the common ability of group 1 and 17 to form -1 ions. I don’t think that is very significant in the context of a general article about nonmetals, and so I think that whole paragraph should be deleted. YBG (talk) 06:24, 27 October 2023 (UTC) I can agree with this, since −1 anions are not too characteristic of alkali metals even though they are mostly possible (for Li it is not even known yet, IIRC). Probably Au with actual aurides is a better comparison to the halogens, though off the top of my head I can't remember if it's been done in RS. Double sharp (talk) 16:05, 27 October 2023 (UTC) @YBG and Double sharp: Thanks. I've previously addressed the 1st para. issue, and mentioned the removal of all the image pairs. Regarding −1 alkalide anions, the context is: Nonmetals cannot be understood without appreciating metals i.e. the name "nonmetal" includes the term "metal". Please further see the two tables of comparative properties at the end of the article, both of which include a metals column. As noted, many nonmetallic elements have some metallic aspects; and many metallic elements (including e.g. Au) have some nonmetallic aspects. Hence the comparison with metals is relevant and fruitful. The synthesis of a crystalline salt of the sodium anion Na– was reported in 1974. It represented the second major overturning of conventional wisdom (Dye at al. 2006, p. 206), the first being the preparation of a noble gas compound in 1962. Since then further compounds (“alkalides”) containing anions of the other alkali metals (bar Li and Fr) as well as that of Ba(!), have been prepared. The relationship between the halogen nonmetals and alkali metals goes the other way: isolable salts containing diatomic or polyatomic cations of Cl, Br and I have been prepared (Wiberg 2001, pp. 419–421; Greenwood & Ernshaw 2002, p. 99). In the context of illustating 1 and 2 above, I feel the existence of −1 alkalide anions is noteworthy and interesting (noting this mention does not occur until the penultimate para. of the sub-section). Dye et al. 2006, "Role of cation complexants in the synthesis of alkalides and electrides", Advances in Inorganic Chemistry, 205–231. doi:10.1016/s0898-8838(06)59006-3 --- Sandbh (talk) 05:43, 29 October 2023 (UTC) @Sandbh: Re my recent 1st paragraph additions: I am well aware that your penultimate paragraph included information about the category-pair comparisons. My recent additions included the only information from those paragraphs that IMO is needed. The remainder of the comparison paragraphs seems to violate FAC criteria 4 It stays focused on the main topic without going into unnecessary detail. YBG (talk) 05:57, 29 October 2023 (UTC) I am not convinced that this is so relevant. Homopolycations aren't by any means restricted to the halogens. They are quite normal for the chalcogens too. It's been known since 1804 (Buchholz) that sulfur dissolves in oleum to give Sn2+ cations, and selenium and tellurium behave similarly (it's in the Greenwood and Earnshaw chapters on these elements). Salts of these chalcogen and halogen homopolycations are certainly less exotic than alkalides in another way; the counter-ion does not need special protection, as is normally needed for alkalides. That's why I'd think that Au is a better comparison to halogens, considering RbAu and CsAu. I'm obviously impressed by the immense skill that goes into preparing alkalides, but there we are talking about an odd sideline of a set of elements that seems to be as far from nonmetallic as possible. Is it really the most relevant possible comparison? I don't think so. I guess maybe one could compare these polycations with Zintl polyanions like Pb94−, but since I'm saying that off the top of my head, I'd like to see evidence from RS that any comparison you decide to put in is actually normal. Double sharp (talk) 08:26, 29 October 2023 (UTC) @Double sharp: Yes, I agree. I mentioned the halogen homopolycations in passing, in item #4 above. The context was that most metals have some nonmetal properties and vice versa e.g. most alkali metals can form –1 anions and most halogen nonmetals can form homopolycations. I suppose the halogen nonmetals could be expected to be among the unlikeliest of all to form cations (except for the NG). That was all. Comment: Gold has some halogen-like properties. Too, it is known as the +1 cation as are the alkali metals. The stoichiometry of Au(I) compounds often resembles that of alkali metal compounds, where the gold cation takes on a similar role to the alkali metal cation (e.g., Na+ or K+). Gold is able to form a –1 cation (more notably when combined with the heavier alkali metals), as are most of the alkali metals in alkalides. And Cs, which is in the same period as Au, has a pale golden tint. --- Sandbh (talk) 06:57, 30 October 2023 (UTC) @Sandbh: If the point is "most metals have some nonmetal properties and vice versa", then sure, I agree. That is something worth saying in this article, and ties into what I said about the outliers. But if that is really all there is to it, then I am not convinced that it really supports the idea of a special relationship between halogens and alkali metals in terms of similarity (other than in terms of sheer contrast). Many metals are known in negative oxidation states, and basically all nonmetals but F and light noble gases (He, Ne, Ar) are known in positive oxidation states. If we forget about oxidation states and start talking about the actual charges (which are often very different), than even F can take a partial positive charge in AuF5·F2 (ref). Does that mean F is metal-like? Not in any very important way, I think. Double sharp (talk) 07:10, 30 October 2023 (UTC) @Double sharp: Thanks. I'm not sure the article sufficiently articulates the fact that "most metals have some nonmetal properties and vice versa". So that's something to look at later on. There's a long history in the literature of a generalised pattern across the periodic table of highly active to less active (even noble) metals and a corresponding trend of less active (even noble) to highly active nonmetals. It's in this context that the comparison between alkali metals and halogens forms part of Chemistry 101. The similarities that come to mind are (i) relatively high reactivity; (ii) capacity for ionic bonding and salt formation; (iii) one set wants to give away an electron while the other wants to gain an electron, both in pursuit of a noble gas configuration; (iv) the two sets have a great attraction to one another. To which can be added the capacity of most of the alkali metals to form –1 anions, a finding that represented the second great upending of chemistry wisdom, the 1st being the discovery that xenon formed a compound. Wiberg apparently thinks the prospect of a trifluro-cation F3+ is sufficiently interesting to make mention of it while noting it is thus far unknown (p. 421). There was a flurry of excitement in 2013 as to the apparently unprecedented preparation of an F atom with a positive charge on it. It was subsequently claimed by Christie et al. (2017) doi:10.1016/j.jfluchem.2017.09.011, by my reading, that the fluorine atoms of interest only had a reduced negative charge. Since F has such a high electronegativity then, yes, I feel that F with a positive rather than negative charge on it would represent noteworthy metal-like behaviour. --- Sandbh (talk) 02:08, 31 October 2023 (UTC) @YBG: In response to your 05:57, 29 October 2023 (UTC) concerning recent 1st paragraph additions: Thanks. I explained the relevance of −1 alkalide anions in my 5 numbered points above, especially points 1 and 2, and 5. What is it specifically about this one sentence (out of the 13 in the sub-section) that represents "unnecessary" detail, noting I left out mention of halogen cations? In considering your response, I feel that there are two other FAC criteria worth noting: 1a. well-written: its prose is engaging and of a professional standard; and 1b. comprehensive: it neglects no major facts or details and places the subject in context. Re 1a., I've aimed to provide a well-written and engaging article rather than a cookie-cutter recycling of vanilla information. Engaging prose includes valuable context, and details that add depth, substance, and value to the content as I've sought to do in this case. Re 1b., the (important) fact and context is that most metals have some nonmetal properties, and vice-versa, and that this is illustrated by the further parallel between halogen nonmetals and most alkali metals both being able to form -1 anions. The inclusion of this detail provides depth, and completeness to the article's coverage of nonmetals. As well as these two extra FAC criteria, it is the lede where the general overview is provided. The main body of the article is then where the details are fleshed out, and the topic made more complete. --- Sandbh (talk) 11:50, 30 October 2023 (UTC) The -1 anion of alkali nonmetals is most certainly not a major fact or detail about halogen nonmetals, much less about nonmetals. It is an interesting factoid about alkali metals, and per 1b it is included in that article. IMO mentioning it here does nothing to make this article more engaging. YBG (talk) 15:09, 30 October 2023 (UTC) @YBG: Thanks. I feel that the –1 anion of alkali nonmetals is a major detail in the context of comparing halogen nonmetals with their alkali metal counterparts. It is a major detail in the context of nonmetal properties occurring in metals. Providing context around the subject matter can help reader engagement via being able to better understand and connect with the topic. While the –1 anion of alkali nonmetals would be no surprise to a chemist it may surprise the general reader relying on memories of high school chemistry. Engaging prose goes beyond presenting basic facts and information. Including such an intriguing or unexpected fact (for a general reader) can improve engagement by piquing their curiosity and encouraging them to continue reading. Taken out context it can be regarded as a factoid; it is more than that in terms of context and enagement. --- Sandbh (talk) 01:51, 31 October 2023 (UTC) @Sandbh, I’m not convinced. @Double sharp, what do you think? YBG (talk) 02:03, 31 October 2023 (UTC) @YBG: I've attempted to give multiple literature- and FAC criteria-based reasons why some of the relatively short content connected with pairing mentions should not be of concern. An elaboration of specific reasons for not being convinced would be helpful. Thanks. --- Sandbh (talk) 02:17, 31 October 2023 (UTC) I disagree with your assumption that it is a major detail. As @Double sharp pointed out above, it is not terribly significant in establishing a relationship between group 1 and group 17. Even if it were a property shared only by these two groups (which apparently it is not), the fact that it is very common for group 17 and very rare for group 1 would make it quite a minor point of correspondence. It seems to me that if you were not so determined to include all these correspondences, you would easily recognize its insignificance. YBG (talk) 05:40, 31 October 2023 (UTC) I agree with YBG. Double sharp (talk) 07:32, 31 October 2023 (UTC) @YBG and Double sharp: Thank you. I've changed the halogen nonmetals similarity paragraph to read as follows: The halogens in group 17 find their counterparts in the alkali metals, such as sodium and potassium, in group 1. Correspondences between the two sets extend to high reactivity; the pursuit of a noble gas configuration; a common valence of one; the alkali metals being very similar to one another as are the halogens; and that hydrogen tends to be placed at the top of either the alkali metals (usually) or the halogens (less often).[147][n20] Mention of –1 anions of alkali metals is now in a footnote. Please bear in mind that my argument, now concerning a footnote, is not limited to criteria 1b on including major facts and details. I also presented arguments pursuant to criteria 1a. On criteria 1b, the major idea is the alkali metal–halogen comparison. Alkalides are one of several supporting details such as high reactivity. The existence of –1 anions is a property shared by Na-K-Rb-Cs and F-Cl-Br-I. Across the periodic table there is no other comparison of this magnitude (AFAIK). Yes, in one sense, it is rare. That said it was the 2nd major overturning of chemistry wisdom. This makes it a big deal namely the idea that alkali metals could be present as –1 anions in compounds. Massey (2000, Main Group Chemistry, p. 113) wrote that this was an "extraordinary" development. Greenwood & Earnshaw wrote, "The chemistry of even the simplest elements has been considerably enriched during the past few years, sometimes by quite dramatic advances ... The chemistry of the alkali metals has a complexity that was undreamt of one or two decades ago ... Compounds of alkali metal anions and even electrides are known." (p. xix). That G&E felt –1 alkali metal anions were important enough to mention in the preface to their second edition is notable. As McCleverty & Meyer (2003) wrote, "The field of alkalides ... expanded tremendously in the 1980s and 1990s." --- Sandbh (talk) 00:44, 3 November 2023 (UTC) @Sandbh The -1 story is a big deal about alkali metals, but in the context of the subject of this article - nonmetals - it is only very tangentially related and not worth any mention at all. I begrudgingly accept it in a footnote. YBG (talk) 04:46, 3 November 2023 (UTC)

Quote boxes

resolved YBG (talk) 15:13, 30 October 2023 (UTC)

The halogen nonmetal quote box would be a great quote IF the subject of this section were the comparison of groups 1&17 - or IF the subject were L-R PT trends. But it is neither. The subject of this section is halogen nonmetals as a type of nonmetal. Better to find another article for this quote. Furthermore, having 5 elipses and one bracketed addition in a relatively short quote seems problematic. Just how much was left out? Finally, when a section has a pic, a high bar must be reached to also have a quote box. That bar is far from met. Best to drop the quote box. YBG (talk) 06:24, 27 October 2023 (UTC) Done. --- Sandbh (talk) 05:45, 29 October 2023 (UTC) Thank you. This is now resolved. YBG (talk) 05:47, 29 October 2023 (UTC)

Metalloid outliers

resolved YBG (talk) 15:13, 30 October 2023 (UTC)

These outliers properly form a small part of the discussion of metalloids, which are but one of several types of nonmetals, and the types are just one aspect of the discussion of nonmetals. So outlier metalloids are just a small part of a small part of a small part of the subject of nonmetals. So while I think the outliers should be mentioned, five longish paragraphs and a picture seems WAY too much. Please collapse this section into a single sentence or at the very most a paragraph. YBG (talk) 06:24, 27 October 2023 (UTC) Since I'm the one who asked for some mention of the outliers, I'll add here that I'd be OK with YBG's proposal. Double sharp (talk) 10:02, 27 October 2023 (UTC) Done. I've replaced the Outliers sub-sub section with a footnote, wikilinked to the Lists of metalloids article. --- Sandbh (talk) 11:18, 28 October 2023 (UTC) Thank you. Thic concern is now resolved. YBG (talk) 16:55, 28 October 2023 (UTC) @YBG and Sandbh: I've boldly turned this into a short parenthesis (still less than a paragraph), because I think we ought to explain why the mention is relevant in a bit more detail. (It's basically because even elements on the metallic side of this line tend to have significant nonmetal-like properties.) Feel free to revert this (or edit it further) if you disagree. Double sharp (talk) 06:07, 29 October 2023 (UTC) @YBG and Double sharp: Works for me; I've trimmed it a bit. Sandbh (talk) 06:28, 29 October 2023 (UTC)

Unclassified nonmetals

no further action YBG (talk) 15:14, 30 October 2023 (UTC)

Just wondering … would it be good to change Unclassified nonmetals to ”Unclassified” nonmetals or even ”Other” nonmetals? In the introduction to Types, it seems it would read very well to say  • a set of unclassified “other” nonmetals, encompassing … instead of  • a set of unclassified nonmetals, encompassing … The addition of quotes (pardon their curliness here) might signify that this is descriptive not actual category name. Thoughts? YBG (talk) 15:44, 27 October 2023 (UTC) @YBG: There's a footnote at the end of the unclassified nonmetals bullet point to which I've added a separate sentence that goes, "The descriptive phrase unclassified nonmetals is used here for convenience." I hope that works. --- Sandbh (talk) 06:19, 29 October 2023 (UTC) I don't know if that footnote is needed or not. My comment here about using quote marks was not a request for any specific action. Rather, I was offering a specific idea - the quote marks - as a possible solution to a problem we’ve wrestled with for years. My thought was, if this idea seems to help, please use it. But if this idea does not, feel free to disregard my post completely, no action is needed. So if you don’t think the footnote is needed or helpful, feel free to remove it. YBG (talk) 01:32, 30 October 2023 (UTC) NFA required. --- Sandbh (talk) 07:04, 30 October 2023 (UTC)

More re complementary pairs

Metalloid / PTM comparison

Resolved YBG (talk) 21:14, 17 November 2023 (UTC)

The penultimate paragraph with block quote amounts to saying “The metalloids and PTM are in the middle of the periodic table, one is weakly metallic, the other weakly nonmetallic”. This is not really a fact about the M-oids and PTM, but rather a fact about the general strongly-metallic-to-strongly-nonmetallic PT trend. The text admits that the comparison is only occasionally made. Unlike the group 17 and 18 comparisons, I don't think this paragraph has anything substantial enough here to be included in the 1st paragraph of the section as I added in the now reverted edits. Best to simply delete this paragraph. YBG (talk) 15:39, 30 October 2023 (UTC) @Sandbh, @Double sharp. I’ve seen no word of agreement or disagreement with my suggestion that this paragraph is not needed and should be removed. Thoughts? YBG (talk) 05:06, 3 November 2023 (UTC) @YBG: I agree with you. Double sharp (talk) 08:21, 3 November 2023 (UTC) Ok, I’ve removed this paragraph. YBG (talk) 13:10, 3 November 2023 (UTC) Done. --- Sandbh (talk) 12:48, 15 November 2023 (UTC)

Unclassified NM / TM comparison

Resolved YBG (talk) 21:15, 17 November 2023 (UTC)

The penultimate “In terms of PT geography...” paragraph essentially says both classes are between more reactive elements and less reactive elements. This is not really a fact about the UNM and TM, but rather a fact about the general strongly-metallic-to-strongly-nonmetallic PT trend. Unlike the group 17 and 18 comparisons, I don't think this paragraph has anything substantial enough here to be included in the 1st paragraph of the section as I added in the now reverted edits. Best to simply delete this paragraph. YBG (talk) 15:39, 30 October 2023 (UTC) @Sandbh, @Double sharp. I’ve seen no word of agreement or disagreement with my suggestion that this paragraph is not needed and should be removed. Thoughts? YBG (talk) 05:05, 3 November 2023 (UTC) @YBG: I agree with you. Double sharp (talk) 05:09, 3 November 2023 (UTC) Ok, I’ve removed this paragraph. YBG (talk) 13:10, 3 November 2023 (UTC) Done. --- Sandbh (talk) 12:48, 15 November 2023 (UTC)

Comparisons in general

resolved YBG (talk) 05:24, 29 November 2023 (UTC)

If you are willing to delete all four comparison paragraphs, I would entertain the addition at the end of the introduction to Types, a general statement describing NM L-R trend, mentioning that it mostly mirrors the L-R trend in metals. If this seems a good idea, let me know and once all four comparison paragraphs are removed, I'll add it from my offline draft. YBG (talk) 15:39, 30 October 2023 (UTC) @YBG: I've deleted all four paragraphs, and added one paragraph to the end of the intro to Types section, explaining that a broadly comparable range of types occurs among the metals, from highly reactive to less reactive (even noble). @Double sharp: FYI. --- Sandbh (talk) 22:25, 14 November 2023 (UTC) @Sandbh, @Double sharp: I added a new comparison paragraph then removed the old one, and finally reverted those changes leaving no differences. Please comment after looking at the new version to see how it flows; or you could see both with the fuzziness paragraphs between. I will consider any comments before restoring my new version in a day or two. I can already see a couple of places where I could make my proposed text read smoother. YBG (talk) 06:48, 15 November 2023 (UTC) @YBG: Thanks. I hope to be able to carefully scrutinize this tomorrow morning my time. --- Sandbh (talk) 12:57, 15 November 2023 (UTC) Sandbh’s analysis of YBG’s alternative @YBG and Double sharp: Here are the topic sentences of the Types section including YBG's paragraph: The classification of nonmetals can vary, with approaches ranging from as few as two types to as many as six or seven. Traversing the periodic table from right to left, three or four types of nonmetals can be discerned: In the periodic table, metalloids – so metallic they are often not considered nonmetals – come beside post-transition metals, the least metallic of metals. The boundaries between these sets of nonmetals are not sharp. The greatest discrepancy between authors occurs in the metalloid "frontier territory" A broadly comparable range of types occurs among the metals, from highly reactive to less reactive (even noble). Topic sentence 3 breaks the logical flow of ideas. It is not a topic sentence as it does not set out the broad premise of the paragraph. Inserting a paragraph mentioning metals here, rather than at the end of the section, is awkward. YBG, your paragraph in full reads: In the periodic table, metalloids – so metallic they are often not considered nonmetals – come beside post-transition metals, the least metallic of metals. This follows a general left-to-right metallic-to-nonmetallic trend. Surrounding these are more reactive elements (transition metals and unclassified nonmetals); and further outside, the most reactive elements (alkali and alkaline earth metals and halogen nonmetals). The least reactive elements include noble gases on the far right and noble metals buried within transition metals. The statement, "metalloids – so metallic they are often not considered nonmetals" is dubious. Only about 50% of authors actually mention lists of metalloids. It has been know for over a century that metalloids behave chemically mainly like nonmetals. Re, "post-transition metals, the least metallic of metals" that is not so. There are overlaps between the metal types, as is the case with the nonmetal types. Towards the middle of the periodic table are transition metals, such as scandium, iron and nickel, of high to low reactivity. To the right of the transition metals, (from group 13 onwards) are metals such as tin and lead, none of which are particularly reactive. For comparison, here's the last paragraph of the section: A broadly comparable range of types occurs among the metals, from highly reactive to less reactive (even noble). On the left side of the periodic table, and below its main body, are highly to fairly reactive metals, such as sodium, calcium and uranium. Towards the middle of the periodic table are transition metals, such as scandium, iron and nickel, of high to low reactivity. To the right of the transition metals, (from group 13 onwards) are metals such as tin and lead, none of which are particularly reactive.[n 24] A subset of the transition metals (including platinum and gold) are referred to as noble metals on account of their reluctance to engage in chemical activity.[133] Note 24 says: For aluminium, Whitten and Davis[134] write, "[It] is quite reactive, but a thin, transparent film of Al2O3 forms when Al comes into contact with air. This protects it from further oxidation For this reason it is even passive toward nitric acid (HNO3), a strong oxidizing agent. When the oxide coating is sanded off, Al reacts vigorously with HNO3." --- Sandbh (talk) 02:01, 16 November 2023 (UTC) I've further copy edited the last para of this section, and added an image. --- Sandbh (talk) 06:12, 16 November 2023 (UTC) Discussion of YBG’s alternative @Sandbh: Your longish post seems to me to have three main objections, which I would like to discuss individually. I would appreciate your effort to keep your responses brief. YBG (talk) 21:41, 17 November 2023 (UTC) (1) You object to metalloids – so metallic they are often not considered nonmetals. Would it be acceptable to say "sometimes" instead of "often"? YBG (talk) 21:41, 17 November 2023 (UTC) @YBG: I suspect it would not be possible to find a supporting citation that refers to metalloids being "so metallic they are often not considered nonmetals." This is especially so given it has been know for ~120 years that metalloids have a predominately nonmetallic chemistry. --- Sandbh (talk) 12:09, 18 November 2023 (UTC) That doesn't answer my question: would it be acceptable to say so metallic they are sometimes not considered nonmetals? Or perhaps this would be better: so metallic they are sometimes not categorized as nonmetals? YBG (talk) 18:23, 18 November 2023 (UTC) I think YBG is right on this one. Anything that would call the chemistry of Te "predominately nonmetallic" would have a hard time not saying the same of some 4d and 5d transition metals (Te forms cationic species at low pH, W doesn't even do that; all W(VI) species involve oxide ligands, but tellurium forms Te(OH)6). As shown at Nonmetal#Comparison of selected properties, there's actually quite few properties that distinguish metals from metalloids, other than a slightly weaker tendency to form alloys (and even then, intermetallic semiconductors like Mg2Sn, FeGa3, and Be5Pt exist): the metalloids usually fall within the bounds of metals. (Again, this is mostly thanks to the 4d and 5d metals being complete disasters chemically.) Most people using a "metalloid" category treat them as a third class, neither metal nor nonmetal, as YBG's wording would have it. Double sharp (talk) 09:24, 19 November 2023 (UTC) (2) You object to post-transition metals, the least metallic of metals, but then you seem to argue as though I had said "least reactive" instead of "least metallic". There are less reactive metals amongst the TM, but are there any that would be considered less metallic (or more nonmetallic) than the PTM? YBG (talk) 21:41, 17 November 2023 (UTC) @YBG: Ditto; I suspect it would not be possible to find a supporting citation that refers to the PTM as being "the least metallic". OTOH the way the paragraph is constructed now is covered by just one citation. I tried to not use the expression PTM here in order to avoid any controversy as to whether Al is or is not a PTM. If it is regarded as such, then a case could be made that Zn is less metallic than Al. This treads on another controversy as to whether Zn is a transition metal. --- Sandbh (talk) 12:09, 18 November 2023 (UTC) @Sandbh: A couple of questions. (a) Is it true that the PTM is the least metallic class of metals? (b) Is it true that in each period, every PTM is less metallic than any AEM/AM/TM in the same period? I'm definitely not suggesting that we'd use either of these convoluted expressions - I'm just trying to verify my understanding of the situation. YBG (talk) 18:40, 18 November 2023 (UTC) Not Sandbh, but: (a) not really, the 4d and 5d transition metals are weaker; (b) not really, as in particular thallium is a better metal than tungsten is, and both are in period 6. (Tungsten doesn't even form any ionic halides; in high oxidation states it forms molecular compounds like WF6, and in low oxidation states it forms cluster compounds like W6Cl18. It also doesn't have any aqueous cationic chemistry to speak of, and the most stable oxide WO3 is more acidic than Sb2O3. On the other hand, Tl+ does an okay job of pretending to be an alkali metal cation, and TlF can quite reasonably be described as ionic, although high conductivity of Tl2O3 shows that it's still a weak metal.) Double sharp (talk) 04:59, 19 November 2023 (UTC) @Double sharp: When you say the 4d and 5d transition metals are weaker, is “weaker” a synonym for “less metallic” (ie, “more nonmetallic”)? YBG (talk) 23:13, 19 November 2023 (UTC) @YBG: Yes. Double sharp (talk) 02:20, 20 November 2023 (UTC) @YBG: (a) Yes. In general terms, the metals to the right of the TM, as a set, are the weakest metals. None of them have any real mechanical strength; most of them are pretty weak chemically. OTOH, some of the early TM are chemically quite strong; there are quite few mechanically strong TM; and several of the TM (noble metals) are chemically weak. To the left of the TM are the successively mechanically weaker and chemically stronger Ln/An and group 1–2 metals. You can get a good appreciation of what’s going on by studying the melting point v. electronegativity chart (for all metals), in the post-transition metal article. (b) Yes, bearing in mind metallic character is a combination of physical and chemical attributes, rather than one or the other. On W and Tl, I suggest the chemistry-based shortcomings present in W compared to Tl, are out-muscled by the mechanical strength of W (e.g. tensile strength ~980 MPa cf ~Tl 10; Mohs hardness 7.5 v. 1.2) and its refractoriness (mp 3,695 K cf. Tl 577).--- Sandbh (talk) 03:49, 20 November 2023 (UTC) Which metals are "weakest" depends on precisely what you're talking about. Chemically, 4d and 5d metals are the weakest. Physically, they are the strongest. Chemically, alkali metals are the strongest. Physically, they are the weakest. For this reason, when talking about metallic strength, it should be clarified what precisely is being compared. Since you were writing about chemical behaviour above, I responded by comparing chemically; if you want to consider both, then any such statement would depend on how you weight the two kinds of properties, and that starts to get into OR. BTW, tellurium (which isn't even a metal) beats thallium on all three physical properties you mentioned (tensile strength 11 MPa vs. 10 MPa, Mohs hardness 2.25 vs 1.2, mp 723 K vs 577), so it's not even that clear that they're good gauges of what good metallicity is. Double sharp (talk) 05:34, 20 November 2023 (UTC) I suggest any concerns about the Mohs hardness of thallium and its lower melting point are out-weighed by the fact that is is a malleable and sectile close-packed metal, with an ionization energy less than 750 kJ/mol, and an EN < 1.9. In contrast, tellurium is a brittle and crumbly open-packed semiconductor with an ionisation energy > 750 kJ/mol, and an EN >= 1.9. That thallium has a metallic chemistry and tellurium has a nonmetallic chemistry is a further consideration. Sandbh (talk) 11:03, 23 November 2023 (UTC) Aren't you kind of proving my point about it not being clear that those properties are good gauges of what good metallicity is? :) Point being, there are a bunch of things that have be considered representative of "metallicity"; since they don't always agree, it's helpful to specify what exactly is meant. Double sharp (talk) 15:34, 23 November 2023 (UTC) (3) You object to how my paragraph fits into the section flow. I need to think about this more. Let’s wait until after we discuss the other two issues. YBG (talk) 21:41, 17 November 2023 (UTC) First of all, the topic sentence of a paragraph needn’t be the first sentence; in my paragraph, the topic sentence was the second one. Nevertheless I’m happy to follow this style since it has been used throughout the rest of this article. I have recast my paragraph taking into consideration the comments received above. These categories follow the general left-to-right metallic-to-nonmetallic trend in the periodic table. The metalloids – so metallic they are sometimes not considered nonmetals – are just right of the post-transition metals – the least metallic class of metals. Surrounding these are more reactive elements (transition metals and unclassified nonmetals); and further outside, the most reactive elements (alkali and alkaline earth metals and halogen nonmetals). The least reactive elements include noble gases on the far right and noble metals buried within transition metals. @Sandbh, @Double sharp, (and any others), any feedback on this revised paragraph? YBG (talk) 19:45, 20 November 2023 (UTC) @YBG: The problem with this wording is that the noble metals are a subset of the transition metals, and in fact are almost right next to the PTM (Hg is already quite noble, and Au certainly is). In general, "metallic character increases going left to right" is one of those lies to children that works because it's correct for the elements encountered in the first year of chemistry. It's not really accurate once you consider the d-block elements (actinoids also have some problems with this generalisation, but the d-block has the most exceptions). Nonmetals don't have this problem, but metals do. Double sharp (talk) 09:50, 22 November 2023 (UTC) @YBG and Double sharp: There is in fact a general trend of increasing electronegativity from Cs to F. Please see Electronegativity: A three-part wave. As DS noted, however, the noble metals are geographically positioned before the post-transition metals. Another issue is that the proposed paragraph mixes the concepts of metallicity with reactivity, which can be confusing. Finally, I’m not sure that supporting citations will be able to be found. The existing form of wording in the article does not suffer from any of these issues. Given this, and speaking frankly, I no longer know why your form of wording YBG, is still being discussed. Sandbh (talk) 10:41, 23 November 2023 (UTC) While the 3- or 4-fold division of nonmetals is well attested, it is my understanding that there is precious little literature support for a comparable division of metals; it isn’t even mentioned at metal § Categories. The multiple pages listed in the ref may all support this 4-fold division or perhaps the division is synthesized from multiple tangential comparisons. Without seeing the original, I hope the former but suspect the latter. I think the noble metals being a subset of the transition metals is the reason why this beautiful and symmetrical scheme has not attracted greater interest. @Sandbh and I both mention reactivity to justify the pairings. I mention metallicity to place these two 4-fold divisions in the broader PT context. Without the metallicity and PT context, there seems to be little justification for including either paragraph, mine or @Sandbh‘s. Although i prefer my approach (seeing the categories as a reflection on metallicity trends) to Sandbh’s, I frankly think the article would be better without either of these paragraphs. @Double sharp, what do you think? Would the article be better without a paragraph comparing the NM categories to M categories? If you want such a paragraph, do you prefer an approach using the M-to-NM trend or one without? YBG (talk) 17:50, 23 November 2023 (UTC) @YBG: It’s not clear to me why there is so much ado over a single paragraph that takes up ca. 1% of the article’s size. I’m currently time-challenged and hope to be able to add some further comments later on. Sandbh (talk) 21:59, 23 November 2023 (UTC) @YBG: A key consideration is that the article opens with a reference to metallic properties and concludes with a comparison of metals and nonmetals. In this context the mid-way broad comparison seems appropriate. The citation is to Parish's book, The Metallic Elements. He surveys the s-block metals; the f-block metals (a chapter each on Ln and An); the d-block metals (a chapter each on the 3d metals, and the 4d-5d metals (including the noble metals); and the p-block metals. The relevant paragraph in the nonmetal article is accompanied by a table showing EN ranges for the elements. The pattern of electronegativity is plain to see. For the types of nonmetals, there is a progression from less electronegative to more electronegative. A similar progression occurs among the metals. Metallicity is broadly related to EN and to reactivity. So, the s- and f-block metals are the most EN/metallic, the ordinary TM are next, then follow the p-block metals, and the noble metals. Among the metals a similar pattern is seen in the melting point v EN chart in the post-transition metals article. Sandbh (talk) 23:54, 23 November 2023 (UTC) So now metallicity is about EN, but when it comes to comparing W and Tl, it's about physical properties? Double sharp (talk) 03:03, 24 November 2023 (UTC) EN is one aspect of metallicity. While there are a fair number of overlaps among the EN values of the elements, and even overlaps between sets of elements, there is no doubting the overall patterns when comparing sets of elements. The scatter chart of EN x MP values confirms this. Sandbh (talk) 06:17, 25 November 2023 (UTC) Differences between authors on how to categorise elements into sets, differences between EN scales (Allen gives much lower values for noble metals than Pauling does), and differences in EN depending on oxidation state (PbII 1.87 versus PbIV 2.33) rather suggests that there is quite a doubt. Double sharp (talk) 13:35, 27 November 2023 (UTC) I may as well gently add, once again, it is well known that both metals and nonmetals range from highly to less reactive (even noble). The paragraph under discussion says just that. Sandbh (talk) 01:25, 24 November 2023 (UTC)

Restating YBG’s questions

Mostly resolved; being refined below in § Types YBG (talk) 03:31, 12 January 2024 (UTC)

Restating and expanding my questions above in hopes of getting direct answers to each, especially from @Double sharp. YBG (talk) 18:57, 25 November 2023 (UTC) I have added responses to each of my four questions by copying extracts from @Double sharp‘s response. Others - especially @Sandbh - are invited to add their own answers to these questions, or even to add additional questions. YBG (talk) 10:31, 7 December 2023 (UTC) I have added section breaks as this discussion has grown longer than I had anticipated. YBG (talk) 06:11, 15 December 2023 (UTC) YBG Q 1 (1) Is it helpful to mention the broad PT trend (L/metal-to-R/nonmetal) when discussing the 4-fold divisions of metals and of nonmetals (and their comparisons) ? YBG (talk) 18:57, 25 November 2023 (UTC) Double sharp commented below I would say yes to (4), which perhaps makes (1) moot. YBG (talk) 10:20, 7 December 2023 (UTC) @YBG: I don't understand your question. Which "broad PT trend (L/metal-to-R/nonmetal)" are you referring to aside from metals on the L and nonmetals on the R? Please bear in mind that the context for the term "nonmetals" is "metals". It is helpful to mention metals in an article on nonmetals for contextual and educational purposes noting most readers are likely to be more familiar with metals. Sandbh (talk) 12:05, 13 December 2023 (UTC) YBG Q 2 (2) How does § Parish (1977, p. 37, 112, 115, 145, 163, 182) present these metal-category-to-nonmetal-category comparisons? Do they reference one another (eg, ‘we see that these p-block metals correspond to metalloids in the same way that noble metals correspond to noble gasses’)? Or are they isolated comparisons without reference to one another? YBG (talk) 18:57, 25 November 2023 (UTC) Double sharp commented below I don't have Parish, so can't answer (2). YBG (talk) 10:21, 7 December 2023 (UTC) @YBG: Parish ("The Metallic Elements") does not have metal-category-to-nonmetal-category comparisons. Rather, he surveys the metals as s-block; 4f-elements; 5f-elements; 3d-metals; 4d- and 5d-metals (inc. a specific early mention of the nobles); and p-block metals: s-block metals---"All the metals are highly reactive, the reactivity increasing with inreasing atomic number." 4f-metals are "fairly reactive...In appearance and reactivity the metals resemble calcium and strontium." 5f-metals are "highly reactive". 3d-metals: "These are the familar metals and several of them are found in everday use...Many...are used for their corrosion resistance, which is chemically rater surprising, since all the metals are expected to very reactive...This apparent anomaly is due to the formation of a closely adherent layer of oxide which protects the underlying metal." 4d- and 5d-metals are "least reactive of all"; noble metals are noted for "chemical inertness". p-metals: "none particulary reactive". Sandbh (talk) 11:26, 13 December 2023 (UTC) Thank you for this listing. So it seems that this source does not in fact present metal-to-nonmetal-category comparisons. (I'd argue that thallium is quite reactive. But that's not the point.) Double sharp (talk) 13:07, 13 December 2023 (UTC) @Double sharp: Yes, that's right. And it is accurate to observe that a broadly comparable range of types occurs among the metals, from highly reactive to less reactive (even noble). As mentioned earlier in the thread, there is a long history in the literature of noting complementing sets of metals and nonmetals. Sandbh (talk) 02:22, 14 December 2023 (UTC) And yet you cannot seem to provide evidence outside your own work for it. The point is, the source you have provided does not appear to support the point of the paragraph without some WP:SYNTH. Double sharp (talk) 02:29, 14 December 2023 (UTC) @Sandbh and YBG: Double sharp (talk) 02:30, 14 December 2023 (UTC) @Double sharp: So, the point of the paragraph is that a broadly comparable range of types occurs among the metals, from highly reactive to less reactive (even noble). I think I would rely on the following citations: 1. "There are groups of elements that have similar properties, including highly reactive metals, less reactive metals, highly reactive nonmetals (such as chlorine, fluorine, and oxygen), and some almost completely nonreactive gases (such as helium and neon)." --- American Association for the Advancement of Science, 1993, Benchmarks for Science Literacy, Oxford University Press, New York, p. 78 2. "The elements change from active metals, to less active metals, to metalloids, to moderately active nonmetals, to very active nonmetals, and to a noble gas." --- Welcher SH 2001, High marks: Regents Chemistry Made Easy, 2nd ed., High Marks Made Easy, New York, p. 3-32 3. "Those [elements] classified as metallic range from the highly reactive sodium and barium to the noble metals, such as gold and platinum. The nonmetals…encompass…the aggressive, highly-oxidizing fluorine and the unreactive gases such as helium." --- Overton et al. 2018, Inorganic Chemistry, 7th ed., Oxford University Press, Oxford, preface Each citation encapsulates the spectrum of reactivity/activity and the transition from metallic to nonmetallic elements across the periodic table. --- Sandbh (talk) 12:44, 14 December 2023 (UTC) I’m coming up for air here. The question raises in this subsection is How does § Parish present these metal-category-to-nonmetal-category comparisons? @Double sharp summarized your answer by saying Parish does not in fact present metal-to-nonmetal-category comparisons, to which @Sandbh replied, Yes, that's right. So the question posed in this subsection has been answered. My apologies for not realizing this earlier. YBG (talk) 14:46, 16 December 2023 (UTC) YBG Q 3 (3) Other than @Sandbh’s own work, how much RS support exists for this 4-fold division of metals? YBG (talk) 18:57, 25 November 2023 (UTC) Double sharp commented below My view for (3) is "not much": for example, when Holleman & Wiberg talk about noble gases vs. noble metals, it's not so much about contrasting nonmetals with metals, but about contrasting main groups with transition groups (i.e. it's really about secondary relationship and Xe and Os having eight valence electrons). YBG (talk) 10:23, 7 December 2023 (UTC) @YBG: The "broadly comparable range of types among the metals" referred to in the paragraph is based on the s-, f-, d- and p-block metals, a "division" which is well-established and widely supported in the literature. The s- and f-block metals are comparable in reactivity; the noble metals are a well-recognised subset of the d-block metals. The reactivity of metals is a frequent and important topic in the literature due to the central role that metals play in various chemical processes and in industrial applications: their reactivity is crucial in various industrial processes, such as metallurgy, catalysis, and the production of alloys, batteries, and electronic components; they are central to electrochemistry, including battery technology and electroplating; understanding and developing these technologies relies on reactivity; the reactivity of metals is important in environmental chemistry, particularly in the context of pollution and remediation; e.g. the mobility and toxicity of heavy metals in the environment are closely related to their chemical reactivity; understanding the reactivity of metals helps in illustrating and applying periodic trends, such as ionization energy and electronegativity;^ it's also important in theoretical and computational chemistry for predicting reactivity and designing new materials. ^ The accompanying table showing the distribution of EN values nicely brings out the progression from less electronegative to more electronegative among the nonmetals. A similar progression occurs for the types of metals. Holleman & Wiberg write, "In place of the noble gases, the transition metal grouping has the noble metals." Indeed. Sandbh (talk) 02:07, 14 December 2023 (UTC) @Sandbh The 4-fold division of metals I’m asking about is the one in you mention in the article’s paragraph and in the EN table: (1) s+f block metals, (2) non-noble d-block metals, (3) p-block metals, and (4) noble d-block metals. My question is, how much RS literature is there for this division? A brief answer would be very appreciated either (a) by giving a few RS refs (besides your own) that divide the metals into these four top-level divisions, or else (b) by stating that you can find none. Thank you. YBG (talk) 03:05, 15 December 2023 (UTC) @YBG: Scott & Kanda (1962, p. 385), The Nature of Atoms and Molecules: A General Chemistry, divide the metals into 1. very active (Groups 1 and 2, Al-Sc-Y-Ln-An); 2. ferrous, including Fe and metals frequently used with it (Ti-Ni; Nb, Mo, Ta, W) 3. noble; and 4. soft (very active excluded). King (1995, p. 289), Inorganic Chemistry of the Main Group Elements, discusses in one chapter, the alkali and alkaline earthmetals, and in another the Ln and An on the grounds that Ln chemistry is predominately the chemistry of highly electropostive metals in the +3 state, just as the chemistry of the alkali metals and alkaline metals is the chemistry of highly electropositive metals in the +1 and +2 states. Atkins (1995, pp. 24–25), The Periodic Kingdom: A Journey Into The Land Of The Chemical Elements, writes, "Between the “virulent and violent” metals on the left of the periodic table, and the “calm and contented” metals to the right are the transition metals, which form “a transitional bridge between the two” extremes. NB: The paragraph in question is not about "top-level divisions". It instead refers to a broadly comparable range of types of metals, including the noble metals as a subset of the transition metals. Sandbh (talk) 02:09, 16 December 2023 (UTC) None of these citations use the categorization of the paragraph in question, so it would seem better not to reference these four divisions. It seems this paragraph is not so much about these four (RS unsupported) divisions (top level or otherwise), but rather about the “broad range”. This point, I believe, would be better made without the clutter of listing these four categories and the numerous examples. Why not simply note that the wide range of reactivity of nonmetals is comparable to the wide range of metals, and then list examples from the extremes? YBG (talk) 03:14, 16 December 2023 (UTC) @YBG: Thanks. First, I'd like to add Holtzclaw et al. (1988), General Chemistry, 8th ed. who refer to "active metals", "TM metals", and "post-TM". In their TM chapter they write, "The heavier elements... Ru, Os, Rh, Ir, Pd, and Pt are sometimes called the platinum metals. These elements and Au are particularly nonreactive." For the Ln/REE and An they write (pp. 802–803) that the former are active metals and that the latter have properties similar to the rare earths (apart from showing a much wider range of oxidation numbers). I'll respond more specifically to your suggestion in my next post. Sandbh (talk) 03:24, 16 December 2023 (UTC) @YBG: The paragraph uses s-, f-, d- and p- nomenclature due to, as you've seen, (i) the different ways the literature refers to different kinds of metals in the same vicinities of the PT e.g. the 18 different names for the metals to the right of the TM; (ii) confusion about which elements are TM, as opposed to d-block; and (iii) related confusion about where the PTM start, as opposed to p-block metals. The "broad" qualifier is intended to accomodate the fact that there will be, from source to source, variations at the boundaries. I'm not quite sure what you mean by the 2nd part of your question. You may mean e.g. "Na to Ni, and Au", as "highly reactive to less reactive (even noble)". I feel this would devalue the paragraph, in terms of contextual understanding, educational value, enhancing interest, and a balanced perspective, making it less comprehensive and less informative. In a roughly 8,350 word article on nonmetals a brief mention (~200 words) of the comparable situation on the other side of the fence, would seem to be not unreasonble especially since "non"-metals only have meaning in the context of their opposites. The FAC criteria likewise mention comprehensiveness and neglecting no major facts or details and placing the subject in context. --- Sandbh (talk) 11:41, 16 December 2023 (UTC) The question posed in this subsection was how much RS support exists for this 4-fold division of metals? To this, it seems, the closest example @Sandbh has given is Holtzclaw, which seems to be a (3+1)-fold subdivision. To be fair, Sandbh sometimes expresses his typology of metals in a 3+1 manner. So the answer to this subsection is “a little bit of support, but certainly not widespread”. YBG (talk) 20:54, 16 December 2023 (UTC) @YBG: I recall Cox (2004), Inorganic Chemistry, BIOS Scientific, who refers to: (i) Pre-transition metals (p. 186); (ii) Transition metals (p. 207); (iii) Post-transition metals (p. 186); (iv) Ln and An (Chapter I, pp. 245–252). Separately, he mentions the platinum metals as exacerbating a trend in reduced reactivity (p. 209). The Ln are described as electropositive and reactive elements (p. 246). The early An are described as being similar to TM (p. 249), noting the "more reactive" nature of the early TM (p. 268); the later An are are described as being more similar to the Ln (p. 250). --- Sandbh (talk) 05:53, 18 December 2023 (UTC) This is not an example of your 4-fold or (3+1)-fold typology. It would be a different entry on a List of alternative metal classes. YBG (talk) 14:23, 18 December 2023 (UTC) @YBG: Eh? Cox refers to the pre-transition metals (≈ s-block metals); the transition metals (≈ d-block metals); the post-transition metals (≈ p-block metals); the Ln/An (≈ f-block metals); and the platinum metals (≈ noble metals). The paragraph in question refers to the s- and f-block metals; the transition metals; the p-metals, and the noble metals as a subset of the transition metals. --- Sandbh (talk) 03:48, 20 December 2023 (UTC) Your typology gathers d-block and f-block metals together, which it appears Cox does not. YBG (talk) 05:40, 20 December 2023 (UTC) Oops, I meant to say “s-block and f-block metals”; but Sandbh correctly understood me. YBG (talk) 19:01, 30 December 2023 (UTC) @YBG: Thanks. 1. Pls recall the long history in chemistry of a comparable range of types of metals and nonmetals, such as active metals, less active metals, less active non-metals, active non-metals, and inert gases. 2. Similarly, the article mentions a broadly comparable range of types as highly to fairly reactive s- and f-block metals; transition metals, of high to low reactivity; p-block metals, none particularly reactive; and a subset of the TM (inc. Pt and sometimes Au) called "noble metals" (or platinum metals) due to their inactive nature. 3. Similarities between the s- and f-block metals are well-established in the literature. A. Wiberg (2001, Inorganic Chemistry, pp. 1703, 1720) writes, "The Ln resemble their neighbours to the left in the periodic system, the alkali and alkaline earths... The An are fairly reactive elements, similar in some respects to their still more electropositive neighbors, the AM and AEM." B. Scott & Kanda (1962, p. 385) referred to the "very active metals" as Groups 1 and 2, Al-Sc-Y-Ln-An. C. Hamm (1969, Fundamental Concepts of Chemistry, p. 490) refers to the "most active metals" as "those in groups IA and IIA (and the lanthanides and actinides ...)." D. Siekierski & Burgess (2002, Concise Chemistry of the Elements, pp. 70, 77, 169) note the high electropositivity of the Group 1 and 2 metals (except Be) and the high electropositivity of the Ln and An. --- Sandbh (talk) 12:37, 20 December 2023 (UTC) Similarities are great, but do not make a typology. I do not object to saying that metals, like nonmetals, exhibit a range from very reactive to very unreactive. I object to the way it is presented as a 4-fold (or 3+1-fold) typology if metals. I believe this violates WP:SYNTH; I’m confident @Double sharp agrees), but you believe it is a reasonable use of RS. There is no evidence that any other WP editor agrees with you. I know you don’t believe that your opinion trumps everyone else on WP. If you want to demonstrate a spirit of collaboration, please try revising these paragraphs to remove these SYNTH concerns. Or agree to let someone else have a go. YBG (talk) 21:04, 20 December 2023 (UTC) @YBG: Thanks. WP:SYNTH exists to prevent original research (OR), not synthesis per se. There's no OR in saying there's a comparable range of types among the metals, given the long history in the literature of a recognized pattern of reactivities across both metals and nonmetals e.g. active metals, less active metals, less active non-metals, active non-metals, and inert gases. Such quotes suggest a recognized framework within the field for comparing and contrasting different types of elements based on reactivity. Some relevent citaions are attached. Ergo, there's no OR. On the spirit of collaboration, I feel I've gone to considerable lengths to accommodate your concerns. In the same spirit, I hope you can also extend similar understanding, flexibility and accommodation to my perspectives." 1. "There are groups of elements that have similar properties, including highly reactive metals, less reactive metals, highly reactive nonmetals (such as chlorine, fluorine, and oxygen), and some almost completely nonreactive gases (such as helium and neon)." --- American Association for the Advancement of Science, 1993, Benchmarks for Science Literacy, Oxford University Press, New York, p. 78 2. "The elements change from active metals, to less active metals, to metalloids, to moderately active nonmetals, to very active nonmetals, and to a noble gas." --- Welcher SH 2001, High marks: Regents Chemistry Made Easy, 2nd ed., High Marks Made Easy, New York, p. 3-32 3. "Those [elements] classified as metallic range from the highly reactive sodium and barium to the noble metals, such as gold and platinum. The nonmetals…encompass…the aggressive, highly-oxidizing fluorine and the unreactive gases such as helium." --- Overton et al. 2018, Inorganic Chemistry, 7th ed., Oxford University Press, Oxford, preface Each citation encapsulates the spectrum of reactivity/activity and the comparable transition among metallic to nonmetallic elements across the periodic table. --- Sandbh (talk) 12:44, 14 December 2023 (UTC) Sandbh (talk) 05:00, 21 December 2023 (UTC) @Sandbh: Having recently re-read WP:SYNTH, I am not convinced. IMO, each of these sources use terms like “active” descriptively, not as a typology. I’ve said before, I am willing to consider using these terms descriptively in this article, but I am not willing to concede that these refs support your 4-fold typology. Nevertheless, if you can convince @Double sharp or any other editor that accentuating this 4-fold typology of metals does not violate WP:UNDUE much less WP:SYNTH, I will reconsider my position. Furthermore, I believe your recent introduction of the phrase “long history” also violates WP:SYNTH, unless one of your sources actually makes such a comment. YBG (talk) 05:57, 21 December 2023 (UTC) @YBG: Thanks. 1. I've edited the para. to remove mention of types. It's now a descriptive para. Ditto image notes. Failing this, could you pls read WP:NOTSYNTH, esp. sections 4, 6, 11, 12, 13 and 20. 2. The 4-fold typology is not "my" typology; it's a simple observation of the range of reactivity "types" (with types used in an informal, descriptive sense) mentioned in the literature. 3. Regarding WP:UNDUE, I've already explained that a more specific mention of metals on a taxonomic basis is less common. Accordingly, the one paragraph is limited to 2.5% of the article. 4. The phrase "long history" is a reflection of the fact that the four cited sources span the period 1947 to 2018; I could change this to "recurring" if that would do. --- Sandbh (talk) 10:38, 21 December 2023 (UTC) Further discussion re refining edits (outdent) @Sandbh thanks for your edit, which went a long way to focusing on description rather that typology. I built on this as I further streamlined the paragraph, with an edit summary explains the removal of three quotations. I note in passing that WP:SYNTH is a section in WP:NOR, an enwiki policy, whereas WP:NOTSYNTH is an essay not fully vetted by the community. But let’s not go down the wikilawyering path. After all, I do kinda like your 4-fold typology for all its quirks. I’m just not sure it merits mention here. As to the inclusion of this paragraph and the EN chart accompanying it, my idea is to improve it as best you and I can, then if by its merits it convinces @Double sharp or some other editor that it merits inclusion, well and good. But if not, we should bid the paragraph and chart a fond farewell. YBG (talk) 13:48, 22 December 2023 (UTC) @YBG: At first glance, your edits look quite good :) Am going to look closer now and maybe do some more ce. --- Sandbh (talk) 05:20, 26 December 2023 (UTC) @YBG: Copy edit done. I added mention of the periodc table context. The two quotations you left are VG and nicely illustrative. I know you attempted to address Al by joining the d- and p-blocks together but there is no support in the literature for this. I had to adjust the reactivities and blocks because it is not s/f- high; d- moderate; p- low; and noble least. There is instead some overlap between the blocks. I removed the EN table because, in light of your good work, there seems to be no longer a need for it. How do you feel now about the paragraph? Thanks --- Sandbh (talk) 06:36, 26 December 2023 (UTC) @Sandbh I’ve made some further tweaks. Added level 3 section head, primarily to make editing easier. If it’s not useful to the reader, please don’t delete until early January or so. Rephrased “In a PT context” - (Where else does one find elements?) to mention the general trend. Rephrased “Highly to fairly reactive”, “High to low”. These are arbitrary levels of reactivity. There’s no need for such artificial precision. “Very reactive” and “less reactive” are accurate descriptions. Both d and p are less reactive than s and f. But maybe it would be better to start by saying s/f are “most reactive”? Dropped unhelpful example of relatively unknown scandium. I’m still uncertain why we need a note about aluminium, especially if all we say is that p/d are less reactive than s/f. But I’ve left it in for now. YBG (talk) 07:30, 27 December 2023 (UTC) @YBG: Thanks. The level 3 section head is fine, for now. OK The phrasings such as “Highly to fairly reactive” etc are from Parish (1977); they aren't arbitrary. Parish is careful with his expressions. d is not necessarily less than s/f. The d-metals include metals having high to low reactivities. I gave Sc as an example of a highly reactive d-metal; Fe is moderately so; Ni is fairly laid back. Hence these three metals cover the high to low reactivity span. That said, I've replaced Sc with Ti. The note for Al reflects that fact that descriptions of Al vary. So, e.g. Rayner-Canham treats it as a "chemically weak metal"; whereas Whitten and Davis (1996, p. 853) write, “[It] is quite reactive, but a thin, transparent film of Al2O3 forms etc." I've ce'd the para. accordingly. I replaced U with Ce, as a better example of "fairly reactive". --- Sandbh (talk) 07:23, 28 December 2023 (UTC) Thank you @Sandbh. 3. My objection to the X-to-Y descriptions is not lack of support, but imposing wordiness on readers. 4. Giving examples of various levels of reactivity is beautiful, but only helps readers familiar with Ti/Fe/Ni reactivity. Examples should anchor our prose in what is familiar to the reader. 5. The Al footnote, then, is necessitated by the p-block generalization. A better solution is to avoid that generalization. 6. Replacing well-known U with less-known Ce is unhelpful to our readers. I think the source of our disconnect is that we are crafting our sentences to answer different questions. You ask: How reactive are s/f? Highly to fairly How reactive is d? High to low How reactive is p? Not particularly (footnote Al) Oh, and by the way, noble metals. I avoid the X-to-Y wordiness and the Al footnote by asking these questions: Where are the most reactive metals found? s/f Where are less reactive metals? d/p Where are the least reactive metals? d-block island Both approaches seek to describe the L-to-R trend. Do you think I’ve accurately described our different approaches? YBG (talk) 18:04, 28 December 2023 (UTC) @Sandbh: I have reworded the paragraph accordingly; comments are welcome. I’m particularly interested in whether my previous post accurately describes the difference in our approaches. YBG (talk) 19:54, 28 December 2023 (UTC) Thanks YBG. 3. Agree wordiness is to be avoided; clarity of expression is the goal. 4. Agree anchoring prose in what's familar, where practical. As a technical article, familiarity for all readers won't always be possible. 5. Footnotes provide helpful additional information. That said, the Al footnote is no longer needed given the new wording. 6. Replaced U with Ce, since U is highly reactive (per Parish) whereas Ce is only fairly reactive. Older readers would likely be familar with Ce due to its presence in lighter flints. I've replaced Ce with Nd given the latter's wide use in magnets. Your description of our approaches is fairly good, noting my concerns about mushing d/p. Broadly picking up your structure, I've edited the paragraph, further reducing the word count, and restoring text-source integrity. --- Sandbh (talk) 00:58, 29 December 2023 (UTC) @Sandbh, is there no way to avoid the clumsiness of “highly to fairly reactive metals” and “metals of high to low reactivity”? Yes, I get it, these expressions are used in the sources, but we are not quoting directly, we are paraphrasing, so there is no need to mimic clumsy wording. YBG (talk) 05:12, 29 December 2023 (UTC) @YBG: Thanks. The issues are that the s-block and 5f metals are highly reactive, with the exception of Be, which is not quite so reactive; and the 4f metals are "fairly" reactive, So we have to accomodate Be/4f, hence "highly to fairly". The other issue is (a) some overlap between the s-metals and the early d-metals i.e. some of the earlier d-metals are highly reactive; and (b) some of the non-noble d-metals have low reactivity (and some are in-between). I've edited the paragraph so that it now refers to s/f as "highly to fairly"; d as "varying reactivity", encompassing high to low; and p as less reactive. I feel this better accomodates the distinctions, including the overlapping nature of the d-metals. Sandbh (talk) 01:48, 30 December 2023 (UTC) @Sandbh: I note that you have reverted to describing blocks in terms of reactivity, which brings the boundary fuzziness to the forefront, making description less succinct. I plan to make another stab at describing reactivity in terms of location. Now that I understand the situation better, I think I’ll do a better job of it. YBG (talk) 18:55, 30 December 2023 (UTC) @YBG: Yes, you did a much better job, including accomodating boundary fuzziness. I've made some minor adjustments. The mention of Mg is particularly nice and I learnt something new about its adherant and protective oxide coating. Thanks. --- Sandbh (talk) 01:05, 31 December 2023 (UTC) Sources gathered from elsewhere on this TP Additional source #1 moved from here in § YBG Q 4 to here in § YBG Q 3 by YBG (talk) 07:06, 20 December 2023 (UTC) Cue one more reference: Steele (1966), The Chemistry of the Metallic Elements, most recently cited in 2020. He divides the metals into: alkali (strongly basic, p. 32), alkaline earth (fairly strongly basic, p. 49); inner transition, with the Ln closely resembling the alkaline earths, and the An similar in many ways to the Ln (p. 122); transition; and later b-Subgroup metals of weak electropositive character (p. 67). The noble metals are mentioned for their unreactivity (p. 19). --- Sandbh (talk) 07:59, 19 December 2023 (UTC) Additional source #2 moved from here in § YBG Q 4 to here in § YBG Q 3 by YBG (talk) 07:06, 20 December 2023 (UTC) PS: Barrett & Malati (1998, Fundamentals of Inorganic Chemistry: An Introductory Text for Degree Course Studies, Horwood Publishing) refer to s-block metals (most reactive, p. 159); f-block metals (highly electropositive, p. 275); d-block metals (p. 257); p-block metals (p. 199) and noble metals (p. 273). — Preceding unsigned comment added by Sandbh (talk • contribs) 10:13, 19 December 2023 (UTC) Additional source #3 moved from here in § YBG Q 4 to here in § YBG Q 3 by YBG (talk) 07:06, 20 December 2023 (UTC) PS re RS. Gifford et al. (2011, p. 153) in The Kingfisher Science Encyclopedia, 3rd ed., divide the PT into the s-block and f-block elements, noting that (but for H) the s-block and first row f-block are all very reactive metals (the 2nd row f-elements are radioactive many being synthetic); the d-block elements, which are metals much less reactive than the s-block metals; and the p-block elements, of which Sn and Pb are "typical p-block metals", being softer than d-block metals and less reactive. They refer to gold as a "noble metal" (p. 146) and platinum as examples of the least reactive metals (p. 183). Sandbh (talk) 23:33, 18 December 2023 (UTC) YBG Q 4 (4) Would this article about nonmetals be better without a reference to this 4-fold division of metals? YBG (talk) 18:57, 25 November 2023 (UTC) Double sharp commented below My view for (3) is "not much"…. Thus I would say yes to (4)…. YBG (talk) 10:26, 7 December 2023 (UTC) @YBG: No, quite the contrary, it would be worse, in my view. Since the article discusses the types of nonmetals a brief mention of the range of metal types is beneficial, for the following reasons: Contextual understanding: Mentioning the types of metals, from highly reactive to noble, provides context and a fuller picture of the periodic table. Sandbh (talk) 02:40, 14 December 2023 (UTC) The goal of this article is providing context and a fuller picture of nonmetals, not of the PT as a whole. A comment about the broad range of metals can provide that context without referencing a rather uncommon typology of metals. YBG (talk) 06:07, 18 December 2023 (UTC) @YBG: As noted, appreciating "non"-metals or "not" metals requires at least some understanding of metals and the periodic table e.g. metals on the left but for H; nonmetals on the right. That's far short of providing a picture of the PT as a whole, for which whole books have been written. As noted, the paragraph takes up ~2.4% of the article, and the concept of s-block metals, f-block metals, d-block metals; and the p-block, where metals meet the nonmetals is well established. We may consider Spice (1964) Chemical Binding and Structure, Pergamon Press, who was cited as recently as 2019. He divides the metals into highly electopositive; inner transition ("electropositive"); transition ("fairly electropositive"); and B-subgroup ("not very electropositive"). He mentions gold and the platinum metals in the context of their structures. Sandbh (talk) 00:31, 19 December 2023 (UTC) Educational value: For readers who are more familiar with the properties of metals, comparing them to nonmetals can provide a more intuitive understanding of the latter. Drawing parallels between the types of metals and nonmetals helps in reinforcing the concept that, while metals and nonmetals differ in their properties, they can be appreciated though the same organisational paradigm. Sandbh (talk) 02:40, 14 December 2023 (UTC) Perhaps metals and nonmetals could be appreciated through the same organisational paradigm, but using an organizational paradigm for metals with thin RS support gives an inaccurate impression and so is educationally detrimental. YBG (talk) 06:07, 18 December 2023 (UTC) @YBG: Tx. First an explanation. In general chemistry (GC), the group-by-group (GBG) treatment for the main groups is common. The f-block metals tend to get short shrift, with most of the focus on similarities among the Ln. The TM tend to be addressed by looking mainly at the 3d metals. The other metals :) are located in G13, 14, 15, 16, and 17. The chemistry of the G13 metals is usually done well. The chemistry of the metals in G14, 15, 16 and 17 tends to get mushed into the GC of the Groups in question. But this is not a GC article, and a GBG treatment is not the major focus. An article focused on nonmetals and their taxonomy, including contextual information about their namesake counterparts, is not about GC. Ergo, the fact that such a more specific mention of metals on a taxonomic basis is less common does not mean it conveys an inaccurate impression nor is it educationally detrimental. The educational value is further enhanced by a consistent approach and the careful positioning of the paragraph in question i.e. after the four types of nonmetals are mentioned but before their type-by-type exposition. Cue one more reference: ... Sandbh 07:59, 19 December 2023 (UTC) Additional source #1 moved from here in § YBG Q 4 to here in § YBG Q 3 by YBG (talk) 07:06, 20 December 2023 (UTC) Enhancing interest: For some readers, understanding that there is a broad and comparable range in both metals and nonmetals might pique their interest and encourage them to explore more about these elements and their properties. Sandbh (talk) 02:40, 14 December 2023 (UTC) Yes, understanding … a broad and comparable range in both metals and nonmetals might pique their interest, but this does not require introducing a typology of metals, much less one thin RS support. YBG (talk) 06:07, 18 December 2023 (UTC) @YBG: Yes, I suspect many things can an be argued away on the basis that they are not necessarily required. OTOH, a one paragraph mention adds depth, context, and a structured framework for comparison, enhancing educational value and reader engagement. Which is a lot about what an FAC article would presumably be aiming to achieve. Sandbh (talk) 10:09, 19 December 2023 (UTC) PS: ... Sandbh 10:13, 19 December 2023 (UTC) Additional source #2 moved from here in § YBG Q 4 to here in § YBG Q 3 by YBG (talk) 07:06, 20 December 2023 (UTC) Balanced perspective: Including information about metals ensures a more balanced perspective, preventing the article from being too focused on just one part of the periodic table. It highlights the interconnectedness of different elements in chemistry. Sandbh (talk) 02:40, 14 December 2023 (UTC) I’m not sure at what point an article about nonmetals becomes too focused on … umm … nonmetals. But as we seek a balanced perspective, we should not introduce details about metals with thin RS support that are not even mentioned in the metal article. YBG (talk) 06:07, 18 December 2023 (UTC) @YBG: Tx. The article becomes too focused on nonmetals when it forgets that appreciating "non"-metals (or "not" metals) requires at least some understanding of metals, and the periodic table (e.g. metals on the left; nonmetals on the right). While nonmetals are in some senses the opposite of metals, they share some aspects, e.g. the classic example of uber reactive alkali metals and uber reactive halogens. Inclusion of such content fosters a balanced perspective. Re thin RS support, and as noted, the paragraph takes up ~2.4% of the article. For the metal article, I'm the lead editor. It's not comparable as it hasn't yet had an FAC-standard upgrade. PS re RS. ... Sandbh 23:33, 18 December 2023 (UTC) Additional source #3 moved from here in § YBG Q 4 to here in § YBG Q 3 by YBG (talk) 07:06, 20 December 2023 (UTC) Overall, a brief mention of the types of metals in contrast to nonmetals enriches the article, making it more comprehensive and informative. Sandbh (talk) 02:40, 14 December 2023 (UTC) In summary, I don’t think this particular typology of metals belongs in the nonmetal article. Perhaps it could find a home in a List of alternative metal classes - patterned after List of alternative nonmetal classes (not List of alternative metal artists, LOL). YBG (talk) 06:07, 18 December 2023 (UTC) @YBG: Tx. I've acknowledged and addressed your concerns including in terms of relevance/FA criteria. I've noted this article is not primarily about general chemistry but is instead focused on nonmetals and a taxonomy of same. I've set out how the article is enriched via several benefits. These include: context; well-established notions of s-, f-, d-, p- and noble metals or their effective equivalents; increased understanding and enagagement; a consistent organisational framework; careful positioning of the paragraph; depth; educational value; comprehensiveness, and a balanced perspective. Along the way I added four more references. I'll close the summary with another reference. Wei et al. (2023) doi:10.1039/D3QM00364G examine the uses of metals in the electrocatalysis of CO2, with a view to addressing present-day energy and environmental crises. They parse the metals as follows: s-block metals; p-block metals; d-block metals (including a discussion of noble metals); and f-block metals. --- Sandbh (talk) 23:29, 19 December 2023 (UTC) @Sandbh, I would like to respond to each of your points in turn. Would it be ok if I duplicated tour signature after each point and then answered each in a separate thread? YBG (talk) 01:29, 17 December 2023 (UTC) @YBG: That'd be absolutely OK. Sandbh (talk) 03:38, 18 December 2023 (UTC) @Sandbh: Thanks. I've done so. YBG (talk) 03:43, 18 December 2023 (UTC) @Sandbh Would it be ok if I moved your additional references to the end of the Q3 section so they’re all together? I’ll add “moved to” and “moved from” notes. YBG (talk) 16:38, 19 December 2023 (UTC) @YBG: Yes, of course; please proceed. --- Sandbh (talk) 23:30, 19 December 2023 (UTC) More re YBG Qs (5) (Editors are invited to replace this placeholder text with additional questions.) Thank you! YBG (talk) 18:57, 25 November 2023 (UTC) @YBG: I don't have Parish, so can't answer (2). My view for (3) is "not much": for example, when Holleman & Wiberg talk about noble gases vs. noble metals, it's not so much about contrasting nonmetals with metals, but about contrasting main groups with transition groups (i.e. it's really about secondary relationship and Xe and Os having eight valence electrons). Thus I would say yes to (4), which perhaps makes (1) moot. Double sharp (talk) 04:32, 27 November 2023 (UTC) @Double sharp: I presume that means you favor removing the entire last paragraph, the one just before § Noble gases (correct me if I’m wrong). What about the EN vs. Type chart that comes just before it? (It’s not clear whether it is just illustrating the paragraph re the 4-fold division of metals, or if it is also illustrating the comments in the previous paragraph about electronegativity.) Should the chart be removed completely? Modified to just include nonmetals (and metalloids)? Retained as is with both metals and nonmetals? And if any is to be kept, should it be converted to a wiki table? YBG (talk) 06:09, 27 November 2023 (UTC) @YBG: Personally, I would favour removing it all, because of my answer to (3). It seems to be referenced to a repository of chemical data, so the interpretation inherent in the tabulation is likely OR. At most, a reasonable place for the metal-nonmetal trend to be briefly mentioned would be in the section for metalloids, because the continuity of this trend is why authors differ on which elements to call metalloids. Double sharp (talk) 13:32, 27 November 2023 (UTC) Ok, I’ll remove the graphic and the paragraph. YBG (talk) 13:52, 27 November 2023 (UTC) Removal edit reverted. Since this was not agreed by me, nor was I asked to express my opinion, it remains open to discussion --- Sandbh (talk) 03:12, 2 December 2023 (UTC) @Sandbh: Thank you for responding. I welcome your input; I had expected to hear from you when i pinged you by reference. I look forward to your responses to my four questions (1), (2), (3) and (4). I think it would help keep the discussion on target if you answered each directly following the question itself. If you think there are other important questions, you are welcome to add (5) etc. Thank you. YBG (talk) 06:34, 2 December 2023 (UTC) I think this long but fruitful discussion has now reached its natural end; I can’t think of any significant changes needed to this section now. YBG (talk)< — Preceding undated comment added 03:34, 7 January 2024 (UTC) YBG (talk) 03:25, 12 January 2024 (UTC)

Lead section & paragraph length

Resolved YBG (talk) 01:54, 21 December 2023 (UTC)

Hmm, it seems like the lead section now has a more organic definition of "nonmetal" (although I'll listen to Graham Beards' opinion on the matter). The only thing that comes to mind is that on my screen we have a lot of 2-3 lines long paragraphs; some merging may be warranted. Jo-Jo Eumerus (talk) 10:25, 23 October 2023 (UTC) Tx JJE. The rule of thumb that I use is that no sentence should be longer than 30 words. If it is, then either shorten it or break into two. I was only able to find one sentence in the lede longer than 30 words, in the last para. I've now shortened it to 29 words. --- Sandbh (talk) 12:21, 23 October 2023 (UTC) @Jo-Jo Eumerus, @Sandbh: I trust neither of you mind my moving this exchange into a separate section. It appears to me that JJE is discussing paragraph length, but the reply is about sentence length. I rather like the current lede paragraph lengths with line counts on my screen of (9,11,7,8,10) in portrait mode and (5,6,4,4,5) in landscape mode. As to paragraphs in the rest of the article, the only really short ones are introducing an immediately following list or chart, which I think is appropriate. The longish ones of 10-12 or more lines don’t seem too long. I’m not inclined to merge short paragraphs unless their topics are very similar. YBG (talk) 05:01, 24 October 2023 (UTC) @Jo-Jo Eumerus Is your concern about paragraph lengths resolved? YBG (talk) 16:43, 19 December 2023 (UTC) Aye, seems like. I'll probably perform a proper review on a FAC or a PR, though. Jo-Jo Eumerus (talk) 11:22, 20 December 2023 (UTC)

Whither now (post FAC7)

resolved YBG (talk) 19:23, 20 November 2023 (UTC)

@Sandbh: Thank you for taking the initiative to resolve the outstanding issues in FAC-7. I wonder if it might be wise to see how many of the reviewers would be willing to become co-nominators? I would be willing to do this under certain circumstances, and I think others might also. Convincing previous reviewers to become co-nominators will improve (but delay) the FAC-8 nomination. For me to be willing to do this, I would need to engage with the FA criteria in a way I have not yet done. For each criterion, I would wish to state the extent to which I reviewed it and list any outstanding issues that need to be addressed before I'm willing to become a co-nominator. Potential problems with this: Trying to recruit co-nominators this way might not be viewed well. Reviewers might have conflicting criteria that cannot be satisfied simultaneously. If so, far better for this to surface - and hopefully resolve - before FAC-8 than during it! For example, there is an inherent tension between precision and readability. How can we avoid both over-simplification and over-precision? For example, if not done carefully, adding the "tendency-speak" to make statements precise can cause sentences to be clumsy and wordy. If not done carefully, simplifying sentences can over-simplify things or lead to false statements. It will take perseverence and carefulness to resolve this issue. Is there any interest in pursuing such a process? Is anyone else willing to consider becoming a co-nominator? YBG (talk) 09:34, 23 October 2023 (UTC) I would strongly recommend against renominating so soon unless you have recruited a co-nominator. Otherwise the next FAC might easily degenerate into another wall of text trying the patience of the coordinators. YBG (talk) 00:18, 27 October 2023 (UTC) @YBG: The plan is to not renominate until all the discusssion on this page has been concluded. --- Sandbh (talk) 02:11, 31 October 2023 (UTC) @Sandbh That eliminates my concern about a sudden renomination. Thank you. Do I understand you correctly that you would prefer not having a co-nominator? YBG (talk) 21:45, 17 November 2023 (UTC) @YBG: As I understand it a co-nominator cannot also support or oppose a nomination. --- Sandbh (talk) 11:35, 18 November 2023 (UTC) That makes sense. By definition, a co-nominator supports the nomination. IMO, a co-nomination seems stronger that a mere support, but if you think it is unhelpful or just plain unneeded, I won't press the issue. YBG (talk) 15:08, 18 November 2023 (UTC)

Further comments (because at the FAC7 I stopped at Physical properties)

resolved YBG (talk) 07:35, 15 December 2023 (UTC)

Chemical properties I still don't buy the precise wording at the beginning. If you were going to say nonmetals form acidic oxides, then sure. But not acidic compounds in general. There surely are a lot of organic bases. Even in the inorganic realm, probably ammonia is the most famous base with only nonmetallic elements in its formula. Double sharp (talk) 07:35, 30 October 2023 (UTC) @Double sharp: Thanks. I intend to change this to say: "Nonmetals possess relatively high values of electronegativity[p. 263] and their oxides are typically acidic.[p. 263] The exceptions concern some amphoteric nonmetallic oxides, such as the dioxides of selenium and tellurium (which nevertheless have a bias to acidity),[p. 446][NB] and water, which is a neutral oxide of hydrogen.[p. 659] The page # cites are to Kneen, Rogers and Simpson 1972, Chemistry: Facts, Patterns & Principles. The NB footnote will say, "Germanium (II) (hydr)oxide has been reported to be more basic than acidic.[G&Z]" The cite is doi:10.1016/0022-1902(64)80157-3, which is a primary source, hence the "may". I haven't been able to get a clear read on Ge(II) hence the NB footnote. Your thoughts? --- Sandbh (talk) 13:03, 1 November 2023 (UTC) @Sandbh: Seems good to me. I think that one should connect the high electronegativity of nonmetals to the acidity of their oxides, as is done here (I think that's based on Wulfsberg's books), since you've just mentioned the former. Also relevant is the oxidation state, which is why I2O is amphoteric whereas I2O5 is acidic. As for explicit examples, I'd avoid getting into the weeds, considering that authors vary about what counts as amphoteric. (Somehow I doubt many people consider N2O5 amphoteric even though it has both acidic and basic properties. :D) I'd just suggest that Sb2O3 be used as the exemplar instead; SeO2 and TeO2 are both stronger acids than As2O3, which is sometimes called just plain acidic already. Also, there's a few nonmetals oxides that display neither acidic nor basic properties. So, perhaps something like this would be good: "Nonmetals possess relatively high values of electronegativity, and therefore their oxides are usually acidic. Exceptions occur when the oxidation state is low, the nonmetal is not very electronegative, or both: thus for example H2O and Sb2O3 are amphoteric. A few nonmetal oxides are neutral, such as CO, NO, and N2O." (I wouldn't count F2O, as it's not really an oxide.) Double sharp (talk) 13:32, 1 November 2023 (UTC) @Double sharp: Thanks. I2O apparently reacts with water to give hypoiodous acid. CO and N2O are formally the anhydrides of formic and hyponitrous acid, respectively viz. CO + H2O → H2CO2 (HCOOH, formic acid); N2O + H2O → H2N2O2 (hyponitrous acid). The reference is House JE 2008, Inorganic Chemistry, Elsevier, Amsterdam, p. 441. In water, NO reacts with oxygen to form nitrous acid HNO2. Per your words, I'll change the sentence to: "Nonmetals possess relatively high values of electronegativity, and their oxides are therefore usually acidic. Exceptions occur when the oxidation state is low, the nonmetal is not very electronegative, or both: thus, for example, water H2O and antimony trioxide Sb2O3 are amphoteric. Wulsberg does not mention EN in the context of oxides but does mention low oxidation states. Gervasini (2013) mentions both aspects so I'll cite them. They don't give specific examples of amphoteric oxides so this'll require another cite. Gervasini A 2013, "Characterization of acid–base sites in oxides", in Auroux A (ed.), Calorimetry and Thermal Methods in Catalysis, Springer Science, Heidelberg, pp. 319–352, doi:10.1007/978-3-642-11954-5 --- Sandbh (talk) 01:41, 2 November 2023 (UTC) @Sandbh: Yup, this is fine now. Hypoiodous acid has a high pKa (~11), comparable to clearly amphoteric Sb(OH)3 (11.0 per G&E p. 51) and Al(OH)3 (11.2). Thus it can quite easily end up protonated in aqueous solution. Regarding the neutral oxides, CO and N2O are only formally anhydrides: in practice the reactions with water hardly occur. Greenwood and Earnshaw outright say that N2O cannot be considered the anhydride of hyponitrous acid (p. 444, 2nd ed.): [N2O] is not to be regarded as the anhydride of hyponitrous acid since H2N2O2 is not formed when N2O is dissolved in H2O (a similar relation exists between CO and formic acid). As for NO, the reaction does not occur in the absence of oxygen, though I'll grant that in normal conditions it is there. :) Double sharp (talk) 03:39, 2 November 2023 (UTC) @Double sharp: Curiously, House 2013, Inorganic Chemistry, 2nd ed., p. 427 says that: Because CO is a slightly acidic oxide, it reacts with bases to produce formates. CO + OH− → HCOO− It seems then that the only peculiar oxides are water, being amphoteric, and N2O being neutral. --- Sandbh (talk) 00:55, 10 November 2023 (UTC) Done. (hopefully) --- Sandbh (talk) 03:24, 2 November 2023 (UTC) @Double sharp Does this resolve the concerns raised in this bullet? YBG (talk) 06:17, 15 December 2023 (UTC) @YBG: Yes. Double sharp (talk) 06:43, 15 December 2023 (UTC) Tangentially, why are we looking only at solid nonmetals? Firstly, you're citing each one to its own source, which makes me wonder if it is a SYNTH to look only at them. Secondly, if it were really a characteristic property of nonmetals, then you'd expect that the strongest reactive nonmetals would be even more clear-cut examples. But fluorine reacts with concentrated nitric acid to produce FNO3! I think it would be better just to talk about oxoacids and the acidic hydrides. Double sharp (talk) 07:35, 30 October 2023 (UTC) @Double sharp: Thanks. I was looking at the solid metals given the elemental gases are nonmetals and of the two liquid elements, Br is an insulator (i.e. a nonmetal). Citing each one to its own source strikes me as compiling a list rather than synthesising new knowledge, per se. How do you see that? FNO3 apparently decomposes in water to form O2, OF2, HCl, and HNO3. I guess that makes it an acidic compound. --- Sandbh (talk) 00:00, 2 November 2023 (UTC) The removal is fine with me. The way I see it, if you have a specific source saying the general statement, it's OK to cite illustrative examples to different sources; but if you don't have a specific source saying the general statement, it starts being SYNTH. I think that people usually mean Brønsted acids when "acid" is used without qualification, but this is moot now. Double sharp (talk) 04:07, 2 November 2023 (UTC) I agree with @Double sharp about SYNTH. YBG (talk) 04:33, 3 November 2023 (UTC) Done. (hopefully) --- Sandbh (talk) 03:24, 2 November 2023 (UTC) @Double sharp Does this resolve the concerns raised in this bullet? YBG (talk) 06:17, 15 December 2023 (UTC) @YBG: Yes. Double sharp (talk) 06:43, 15 December 2023 (UTC) 18-electron vs duet/octet is not about metals vs nonmetals, but about transition vs main-group. Obviously, the alkali metals are trying to get a nice, stable full shell; it's just that it's much easier for them to do it by shedding the outermost one. Double sharp (talk) 07:35, 30 October 2023 (UTC) Done. --- Sandbh (talk) 06:47, 8 November 2023 (UTC) @Double sharp Does this resolve the concerns raised in this bullet? YBG (talk) 06:18, 15 December 2023 (UTC) @YBG: Yes. Double sharp (talk) 06:43, 15 December 2023 (UTC) It should probably be noted that these generalisations are at their best for the strongest nonmetals. Near the borderline, especially for the metalloids, it is quite different. I think this article gets at it quite well (section 5), though I wouldn't suggest using its idiosyncratic terminology. The point is that the very strongest nonmetals are really "the opposites of metals" in all ways (i.e. extremely high EN, forming ionic bonds with the metals, being quite happy in negative oxidation states, forming strong acids, and going for simple or hydrated anions in preference to oxyanions), whereas the other ones tend to compromise more. Double sharp (talk) 07:35, 30 October 2023 (UTC) Done. (hopefully). The third paragraph of the Chemical properties subsection now reads: Furthermore, nonmetals typically exhibit higher ionization energies, electron affinities, and standard reduction potentials than metals. Generally, the higher these values are (including electronegativity) the more nonmetallic the element tends to be.[71] For example, the chemically very active nonmetals fluorine, chlorine, bromine, and iodine have an average electronegativity of 3.19—a figure[n 10] higher than that of any individual metal. On the other hand, the 2.05 average[n 11] of the chemically weak metalloid nonmetals falls within the 0.70 to 2.54 range of metals.[72] --- Sandbh (talk) 12:11, 9 November 2023 (UTC) @Double sharp Does this resolve the concerns raised in this bullet? YBG (talk) 06:18, 15 December 2023 (UTC) @YBG: Yes. Double sharp (talk) 06:43, 15 December 2023 (UTC) Are high oxidation states in groups 15 and 16 really unusual? I kind of doubt it considering that this is the majority behaviour. Nitric and sulfuric acids are familiar even in the school chemistry lab. I'd rather name the last section "higher oxidation states" than "unusual oxidation states" for this reason. Double sharp (talk) 07:35, 30 October 2023 (UTC) Done. --- Sandbh (talk) 12:29, 9 November 2023 (UTC) @Sandbh: I still think the "higher oxidation states" section has problems: nitrogen already has oxidation state +5 in nitric acid, which is a familiar compound. Moreover, the actual oxidation states in H2S and HF for the non-hydrogen elements are −2 and −1, not 2 and 1; and the oxidation state of Xe in XeF2 is +2 (for an actual example of +8, you'd need XeO4). Even coordination number isn't an accurate phrasing because of species like NH4+, H3O+, and H2F+. Double sharp (talk) 13:50, 15 November 2023 (UTC) @Double sharp: Thanks. I've rewritten this paragraph to address your well-raised oncerns. PS: I've added a paragraph to this section re multiple bond formation. --- Sandbh (talk) 01:11, 16 November 2023 (UTC) @Double sharp Does this resolve the concerns raised in this bullet? YBG (talk) 06:22, 15 December 2023 (UTC) @YBG: Yes. Double sharp (talk) 06:43, 15 December 2023 (UTC) --- Sandbh (talk) 01:11, 16 November 2023 (UTC) I’ve taken the liberty of adding multiple signatures to facilitate replying to each point independently using the neat new reply feature. @Double sharp, if you object, feel free to revert. YBG (talk) 06:22, 31 October 2023 (UTC) @YBG: No problem. :) Double sharp (talk) 07:01, 31 October 2023 (UTC)

Halogen pic

resolved YBG (talk) 05:52, 31 October 2023 (UTC)

How would something like this work for the picture at Nonmetal § Halogen nonmetals? sodium (Na), chlorine (Cl), and table salt (NaCl) Corrosive chlorine, a halogen nonmetal, combines with highly reactive sodium to form stable, unreactive table salt. YBG (talk) 02:10, 31 October 2023 (UTC) @YBG: It looks pretty, and better than I'd expected, and adds interest to the article. Please proceed. --- Sandbh (talk) 03:28, 31 October 2023 (UTC)

Sources pic

Implemented YBG (talk) 03:50, 7 November 2023 (UTC)

I’m experimenting here with a table to replace the one at § Abundance, extraction, and uses Nonmetallic element sources Group (1, 13-18) Period 13 14 15 16 1 / 17 18 (1-6) H He 1 B C N O F Ne 2 Si P S Cl Ar 3 Ge As Se Br Kr 4 Sb Te I Xe 5 Rn 6    Mineral ores    Mining byproducts    Liquid air    Natural gas    Seawater brine References Differences from the status quo: Corrected Te color Add missing period 1, 5 Group label 1/17 in place of footnote 2-line legend labels 1-line table header Horizontal “Period” label Parenthetical group/period numbers Legend in L-R order instead of top-bottom, which also places similar sources together Wikitable instead of graphic Somewhat mnemonic/symbolic color selection (I don’t feel strongly about this) Iodine’s two colors are diagonal, not horizontal YBG (talk) 15:00, 6 November 2023 (UTC) @Sandb, @Double sharp What do doy think about using this graphic instead of the current one? YBG (talk) 15:40, 6 November 2023 (UTC) @YBG: I like your proposed version, especially because of #9. Double sharp (talk) 15:42, 6 November 2023 (UTC)

Abundance, sources, uses

resolved YBG (talk) 15:10, 18 November 2023 (UTC)

@Sandbh, @Double sharp: What do you think of putting each graphic in its proper section? Check out special:permalink/1183897347 § Abundance, sources, and uses in both desktop and mobile views. YBG (talk) 04:40, 7 November 2023 (UTC) @YBG: I think that will be OK. --- Sandbh (talk) 22:28, 7 November 2023 (UTC) Implemented YBG (talk) 10:11, 8 November 2023 (UTC)}} I subsequently made some additional changes. Here's a link to the latest: Nonmetal § Abundance, sources, and uses Added {{clear}} at the end of each section Removed the table headings expanded section headers Moved the sources legend blocks into the text Some additional changes might be helpful. @User:Sandbh, would you consider looking at these? The uses table refs are identical for each section; it would be nice to have them be more specific The sources table legend is in the text as a table. I'm sure there's a better way to do this, but I don't know what it is. Thanks YBG (talk) 12:09, 8 November 2023 (UTC) @YBG: Uses table cites have been reorganized to be more specific. For now, I'm happy with the sources table legend. @Double sharp: FYI. --- Sandbh (talk) 12:42, 15 November 2023 (UTC) Thanks. BTW, I figured out how to get a hanging indent work with the text, which also serves as the table legend. I want to test it out with a bunch of different screen widths, but once I do I think this whole section is resolved. YBG (talk) 23:00, 16 November 2023 (UTC) And now I've fixed the hanging indent. Everything is resolved in this section. YBG (talk) 05:10, 17 November 2023 (UTC) It looks good. --- Sandbh (talk) 12:12, 18 November 2023 (UTC)

Property comparisons

Why is § Comparison of selected properties in the § History, background, and taxonomy section? These tables that compare the chemical and physical properties of metals and the 3+1 types of nonmetals would seem to be more appropriate either in the Chemical and Physical subsections of § General properties or else at the end of § Types. Thoughts? YBG (talk) 04:58, 17 December 2023 (UTC)

@YBG: It's at the end of the artice as feedback from a previous FAC or review was that the table represent too much "clutter" midway through the article, or words to that effect. --- Sandbh (talk) 04:50, 18 December 2023 (UTC)

That makes sense. My concern is that including them there makes that section seem like a coat rack of marginally related topics. But I don’t have a good alternative right now. YBG (talk) 05:08, 18 December 2023 (UTC)

Yes. In another sense, the article tends to flow from basic definitions and properties to more specific information about types, abundance, and historical background, in just five sections. This approach may help the reader see how current understanding and typology are rooted in historical developments and empirical comparisons. --- Sandbh (talk) 04:05, 20 December 2023 (UTC)

More re types

@Sandbh: I’ve trimmed the descriptions in the list that also serves as a legend. In particular I’ve tried to eliminate the clumsy X-to-Y descriptions. I restored “chemically strong”, it is much crisper than “highly to moderately reactive” and seems supported in the literature. I eliminated “high to low reactivity” which seems to the casual reader (eg FAC evaluators) to be tantamount to meaningless. YBG (talk) 06:07, 31 December 2023 (UTC)

@YBG: I removed the nos. of each type as: after the intro referring to 4 types, there were too many numbers; it isn't necessary to keep track; and the accompanying image does that job. I’ve reinstated mention of the H to M reactive nature of the halogens for 2 main reasons: source-text integrity (regardless how clumsy, not all the halogens are vanilla); and the fact that, as it happens, “chemically strong” is not well-defined in the literature. I reinstated mention of metalloids as "not particularly reactive" as this provides more wriggle room than "relatively unreactive" (As can be a little like Al). This paragraph touches on the heart of the article so I’m particularly invested in it. Sandbh (talk) 11:00, 31 December 2023 (UTC)

@Sandbh: a couple of questions.

1. If having the same absolute level of reactivity isn’t what characterizes the halogens, what does? Can we say they are corrosive? Highly (or relatively) electronegative? Relatively reactive? Very reactive? There must be something they have in common.
2. Can we say that the metalloids are “generally unreactive”?

YBG (talk) 12:02, 31 December 2023 (UTC)

Lifting some descriptions from the subsections, I come up with this:

• relatively inert noble gases
• notably reactive halogen nonmetals —OR— corrosive halogen nonmetals
• less reactive unclassified nonmetals
• generally unreactive metalloids

Thiughts? YBG (talk) 12:19, 31 December 2023 (UTC)

Ok, I’ve implemented these nicely parallel 2-word reactivity descriptions. I’m uncertain whether G17 should be “notably reactive” or “corrosive”; I can live with either. The leftovers are “less reactive” compared to G17, on a period-by-period basis; perhaps that needs a clarifying note but I don’t think so. “Generally unreactive” I think captures the subtleties of the metalloids. YBG (talk) 13:18, 31 December 2023 (UTC)

@YBG: Thanks. *Collectively*, the halogen NM represent the epitome of reactivity. The difficulty is I. It's reactive, sure, but only e.g. a weak oxidising agent, outclassed by O. Among the unclassified NM, O is highly reactive. In c. 2007 the US was losing more than $10 billion each year to corrosion, much due to rusting of iron and steel. The oxidizing agent causing all this is usually O. It further produces molecules of peroxide (O₂^2–) and superoxide (O₂^–), after it reacts during respiration to produce water. These highly reactive forms of O would damage the delicate biological structures within a cell. Consequently, most organisms that breathe air have evolved enzymes to deal with these dangers. "Generally unreactive" works OK for the metalloids. "Notably reactive" works OK for the halogen NM. However, for the UN one would have to say, "notably to less reactive" i.e. that overlap thing is evident again. --- Sandbh (talk) 06:54, 1 January 2024 (UTC)

What about “variably reactive”? YBG (talk) 05:17, 2 January 2024 (UTC)

@Sandbh?? YBG (talk) 05:18, 2 January 2024 (UTC)

@YBG: Thank you. “Variably" reactive sounds like each of the UN are individually variably reactive, which is not so. How about "mixed reactivity”? Then we would have:

• relatively inert noble gases
• notably reactive halogen nonmetals
• mixed reactivity unclassified nonmetals
• generally unreactive metalloids

I like it so much I’ll go ahead and do the edit.

— Sandbh (talk) 10:03, 3 January 2024 (UTC)

Great. I think we’ve resolved all the major issues in this section. YBG (talk) 03:31, 7 January 2024 (UTC)

Single distinguishing properties table

resolved YBG (talk) 03:29, 7 January 2024 (UTC)

As the table cells are advertised as being ordered by date, why not put the year at the beginning of each line, with a different hanging indent so that the year can function as a bullet without needing a bullet icon. YBG (talk) 02:29, 2 January 2024 (UTC) Ok, I’ve tried this and am fairly satisfied with the result except for the fact that the years are proportionally spaced so not uniform in width. But I’m not wedded to it if anyone objects it can be reverted. YBG (talk) 04:40, 2 January 2024 (UTC) Fixed with {{mono}}!! YBG (talk) 04:57, 2 January 2024 (UTC) @YBG: Very nice! --- Sandbh (talk) 07:19, 4 January 2024 (UTC)

Peer review or FAC

@YBG: I feel this article is now good to go to PR or FAC. Do you concur? --- Sandbh (talk) 07:36, 4 January 2024 (UTC)

@Sandbh: Perhaps. Let me take a global look first to see if anything jumps out. YBG (talk) 15:09, 4 January 2024 (UTC)

Types

@Double sharp: after a very long discussion between @Sandbh and me, I think we’ve come about as far as we can. Would you please read the last paragraph of § Types, the one just before § Noble gases dealing with metal reactivity. Is it acceptable in its current form? If not, what changes do you think are necessary? Is the article better with this paragraph or without it? Thanks! YBG (talk) 03:25, 7 January 2024 (UTC)

Personally, I still do not see the point of having this paragraph in the main text. Nonetheless, it is fairly short, and I would be fine with it as a note. Since it is this short, I would also accept leaving it as it stands, although this is not something I would consider ideal. Double sharp (talk) 04:28, 7 January 2024 (UTC)

@Double sharp and YBG: Thanks. I'll look more closely about moving the paragraph into a footnote. Sandbh (talk) 00:49, 8 January 2024 (UTC)

@Double sharp and YBG: I've moved the paragraph into a footnote, at the end of the four bullet points setting out the four types of nonmetals. Sandbh (talk) 05:33, 8 January 2024 (UTC)

@Sandbh, thank you for accommodating this. I think it works as a footnote, but I wonder about the placement and its relevance as it’s current position makes it look as though it is just related to the metalloids.

Currently the lead-in to the four bullets says:

• ... four types of nonmetallic elements can be discerned:

I’m wondering if it would be better like this:

• ... four types of nonmetallic elements of varying degrees of reactivity^{[n 24]} can be discerned:

@Double sharp, before Sandbh it^or I make any changes, I’d appreciate knowing, Do you agree with my concern about placement of the note?

Also, @Sandbh and @Double sharp, what is your preference order for these seven options (and why?):

1. The separate paragraph as it was before Sandbh converted it to a footnote. -- see special:permalink/1194284385#Types
2. The footnote as Sandbh placed it at the end of the metalloid bullet. -- see special:permalink/1194284904#Types
3. The same footnote placed in the lead-in to the bullets, with the added text 'of varying degrees of reactivity' as I showef above.
4. The same footnote in the lead-in but without the added text.
5. Not including the information, neither as a paragraph nor as a note.
6. Remove the reactivity descriptions from the bullet list of nonmetal types and add this sentence separate from the bullets: The halogen nonmetals are notably reactive, the unclassified nonmetals vary widely in reactivity, the metalloids are generally unreactive,^note and the noble gases are generally inert.^note This could be added to the fuzziness paragraph, either as its first or last sentence, or as a one-sentence paragraph between the bullets and the fuzziness.
7. In a separate paragraph just before § Noble gasses, as special:permalink/1195032848#Types.
8. Some other idea (what?).

I can see advantages and disadvantages to the idea I’ve shown above, so I certainly don’t want to propose it until I’ve heard what others think. Thanks in advance for your input. YBG (talk) 06:33, 8 January 2024 (UTC)

@Sandbh and @Double sharp, I’ve added another option to my list. I’m still interested to know your preference order of these options, and whether you share my concern about the placement of the note. YBG (talk) 14:48, 8 January 2024 (UTC)

@YBG: I feel the way the paragraph reads now works well (#2). I like the reactivity descriptors. They give the reader mental markers. --- Sandbh (talk) 11:33, 9 January 2024 (UTC)

@Sandbh How do you prioritize the other options? YBG (talk) 19:24, 9 January 2024 (UTC)

@YBG: I've changed the footnote back to main body text, and added it the end of the section. I feel that the new intro to the resulting para. i.e., "For context", works very nicely. Of the other options my priority list would be 1 (as modified); and then 2 (as modified). None of the other options work for me: 3. because there's more to the types than reactivity; 4. because talking about metals in the lead-in is out of place; 5. because it's inconsistent (the article mentions other comparisons with metals) and non-encyclopedia; 6. because it removes the mental hooks for the reader. So, I guess what I've now done matches 7. --- Sandbh (talk) 00:39, 12 January 2024 (UTC)

@Sandbh - I was hoping you'd wait for @Double sharp to weigh in before making changes. DS, I'd really appreciate knowing how you'd prioritize the options, including the newly added #7? YBG (talk) 03:45, 12 January 2024 (UTC)

@YBG: Personally, I favour a hybrid of what Sandbh has done and #2. I think the wording is fine and good, but my first preference is still for that paragraph to be a footnote, as it is an addition for context that is not directly related to the article's subject. My second preference is to leave things as they currently stand. Double sharp (talk) 03:53, 12 January 2024 (UTC)

@Double sharp: If it is a footnote, what are your preferences for where to place it? YBG (talk) 03:56, 12 January 2024 (UTC)

@YBG: In the same place it would have been as a paragraph, i.e. as a note attached to the previous paragraph. Double sharp (talk) 03:58, 12 January 2024 (UTC)

@Double sharp. OK, you like the present wording, and you prefer footnote > body text. How do you rank omitting it entirely? (a) footnote > body > omit, (b) footnote > omit > body, or (c) omit > footnote > body? YBG (talk) 16:44, 12 January 2024 (UTC)

@YBG and Double sharp: I like Double sharp's solution. YBG: I'm not sure what the basis for the "omit" option is. The article compares nonmetals and nonmetals at four points in the Physical properties section; the same in the Chemical properties section; and comparisons are again made in the Suggested distinguishing criteria section, and the Comparison of selected properties. An article whose name derives from the "metal" word, would presumably include coverage of the contrasts, overlaps, and similarities. --- Sandbh (talk) 07:02, 13 January 2024 (UTC)

@Sandbh, at one time @Double sharp expressed the opinion that the article would be better without what was then a paragraph. I am inquiring to determine to what extent he still might hold that opinion and how that stacks up against the other two options. As to word derivation, I asked your opinion about this fascinating philosophical issue on my talk page. YBG (talk) 18:03, 13 January 2024 (UTC)

Lead-in to types bullets

@YBG: I've changed the mention of number of types to read "three or four types of nonmetallic elements can be most commonly discerned". This is more consistent with the opening paragraph of the section. It also clarifies why "three to four" in that these are the most common approaches. I've used "discerned" rather "seen", as "seen" often refers to the act of visual perception, whereas "discerned" implies a deeper process of understanding, interpreting, or making out something that might not be immediately obvious. I feel this is especially appropriate given the subject matter, including the "are they?/aren't they" nature of the metalloids. --- Sandbh (talk) 00:23, 12 January 2024 (UTC)

@Sandbh What do you think of how it is now? YBG (talk) 18:20, 13 January 2024 (UTC)

I thought this: "In the periodic table, above and to the right of the metals, four types of elements are commonly recognized, from right to left:" was clumsy with its reference to nonmetals being "above" the metals, and the two mentions of "to the right" and "right to left". I've ce'd it to read, "In the periodic table, to the right of the metals, four types of nonmetallic elements can be recognized (proceeding from most to least nonmetallic):" I hope that works. --- Sandbh (talk) 01:00, 14 January 2024 (UTC)

Yea, I think you're right about the clumsiness of my wording. Yours is definitely better.

I am surprised you restored "nonmetallic"; I thought it was the reason for saying "3 or 4" instead of "4". YBG (talk) 01:24, 14 January 2024 (UTC)

A thought on the history

It occurs to me that there must be a missing link between Dupasquier and Dumas on the one hand, and the modern idea on the other, because they consider B and Si to be nonmetals but are not agreed on the more metalloidal elements. Dumas includes As but not Se, and Dupasquier includes Se but not As; neither include Ge, Sb, or Te. The 1911 Britannica article on chemistry thinks that B, Si, Se, and Te are nonmetals, but not Ge, As, and Sb. I assume this changed when people started using "metalloid" for an intermediate set instead, but in that case the inclusion of such elements as primarily nonmetals gets somewhat iffy, since mostly people talk about them as intermediate between metals and nonmetals. Back when there were only two categories and no intermediate ones, it does not seem as though Ge, As, and Sb were considered nonmetals that often. Double sharp (talk) 04:27, 7 January 2024 (UTC)

@Double sharp: Thanks. I've added a paragraph about the metalloids.

Early on the article says, "Nonmetallic chemical elements generally have low density and high electronegativity" and "The six most commonly recognized metalloids have relatively low densities and predominantly nonmetallic chemistry and are typically seen as intermediate between metals and nonmetals;[10] they are included in this article for comparison: B, Si, Ge, As, Sb, Te." The comparison of properties section adds, "The dashed lines around the columns for metalloids signify that the treatment of these elements as a distinct type can vary depending on the author, or classification scheme in use." --- Sandbh (talk) 05:16, 8 January 2024 (UTC)

@Sandbh: Regarding the paragraph: what elements do Newth and Friend consider to be metalloids?

P.S. The discoverers of tellurium certainly thought it was a metal. So did Berzelius, per what Weeks quotes of him in doi:10.1021/ed009p474. So they presumably cannot have thought that it had a "predominantly nonmetallic chemistry": that view must have come later. Speaking a lot earlier, Agricola considered Sb to be as metallic as Pb in De natura fossilium (quoted in Metal#The Renaissance), which makes sense when one considers that Pliny confused the two. J. R. Glauber likewise thought Sb was a metal on a par with Co, Zn, and Bi: Weeks' Discovery of the Elements (p. 144) quotes him as writing And if we nevertheless maintain that each planet gives birth to its own metal, to which star should one assign bismuth, cobalt, antimony, and zinc? On the other hand, on p. 261 of the same book we find a quote of Scheele calling Mo a "half-metal". Double sharp (talk) 06:02, 8 January 2024 (UTC)

@Double sharp: Newth says the following elements encompass metalloid and nonmetals: As, B, Br, C, Cl, F, H, I, N, O, P, Se, Si, S, Te.

Friend says:

"The difficulty of drawing a dividing line between metals and non-metals is clearly shown by the existence of an alternative method of classifying the elements, which divides them into three groups, namely, non-metals, metalloids, and metals. A metalloid is an element which, although it resembles a metal in most characteristics, yet lacks some one or more of the features which typical metals generally present. Usually, the metalloids possess the form or appearance of metals, but are more closely allied to the non-metals in their chemical behaviour. The following elements are included in the metalloids: H, Te, Ge, Sn, Ti, Zr, As, Sb, Bi, V, Cb, Ta, Mo, W, and U."

Berzelius, in 1818, also thought Se was a metal due to its lustre. He subdivided the metals into two classes, those that are capable of forming acids, and those that act as bases: "I place selenium among the acidifiable metals near arsenic." (Trofast J 2011, Berzelius' discovery of selenium, Chemistry International, 33(5), p.16) I guess Dumas (1828) was still going by Berzelius's classification, and that by 1844, Dupasquier (among others) had worked it out.

Agricola (1546) may have considered Sb to a metal on the grounds that "when smelted, a certain portion be added to tin, a bookseller's alloy is produced from which the type is made that is used by those who print books on paper."

I don't know on what basis Pliny confused Sb and Pb. I believe he knew the first was brittle and the second malleable.

In 1658, when Glauber wrote that passage in Opera Chymica (1658), Co, Zn, Sb, and Bi were all considered to be semi-metals, due to being brittle. The ides of associating each of these imperfect "metals" to a planet was, alchemically speaking ... err ... daft.

"Half-metals or semi-metals were substances which resembled the "old" metals in color and density but which had differences in formability. After Georg Brandt's dissertation on the half-metals in 1735 and his discovery of cobalt, six semi-metals were known: mercury, bismuth, zinc, antimony, cobalt and arsenic. When new metals like molybdenum were discovered and prepared, they were often not malleable owing to the presence of impurities and because of that were called semi-metals." Enghag P 2008, Encyclopedia of the Elements, John Wiley & Sons, p. 596.

Sandbh (talk) 12:53, 8 January 2024 (UTC)

@Sandbh: Thanks for the lists: I see Friend is on the Internet Archive. I see Newth does not include Ge and Sb, and it's interesting that Friend considers many of the group IVB through VIB metals as "metalloids" on the grounds of their chemical behaviour. As you know, I would agree with Friend on that (especially for highly electronegative W, which doesn't even manage to form ionic halides). On the other hand, this rather seems to mean that the general idea of "metalloid" among pre-WW2 authors is not the same as the one we have now, and that it was by no means agreed that Ge, As, Sb, and Te were nonmetals then, although people thought B and Si were. Which raises my questions: did most people think Ge, As, Sb, Te were nonmetals around 1900, when it was more common to have only two categories (metals vs nonmetals)? And since the post-WW2 era is when three categories becomes common, is it really justified to consider most of these as nonmetals by default, when most authors nowadays would say that metalloids are something different from both metals and nonmetals? Moreover, doesn't the idea about "relatively low densities and predominantly nonmetallic chemistry" raise questions about Ti, V, and Zr that are all less dense than Sb? (All three are mentioned by Friend as being "more closely allied to the nonmetals" chemically; considering that TiCl₄ and VCl₄ are covalent molecular liquids at room temperature like SiCl₄, and that the Zr⁴⁺ aqua cation is so easily hydrolysed, he has a point!) On these grounds I think I'd be much happier if metalloids were given as a "sometimes" inclusion for comparison rather than as a default fourth category of nonmetals, more like the way elements like C, Al, and Se are treated in metalloid.

Regarding Pliny and Dioscorides, see the passages here. On the one hand Pliny distinguishes "male" and "female" antimony (probably stibnite and metallic antimony respectively); on the other hand, when describing the processing of stibnite, he calls the metallic reduction product lead (faex plumbosissima). Double sharp (talk) 13:32, 8 January 2024 (UTC)

@Double sharp: Thanks. I don’t know where the idea of "relatively low densities and predominantly nonmetallic chemistry" came from. The article refers to including metalloids for comparative purposes and due to their "relatively low densities, high electronegativity, and (nonmetallic) chemical behavior." Ti, V, and Zr have low EN. I’ve changed the text in the Types section so that it now refers to "three to four types", rather than "four". Is that OK? The article otherwise elsewhere mentions the sometimes nature of metalloids as nonmetals, at several points.

I don't know enough about the situation c. 1900.

Germanium has a record of being regarded as a poorly conducting metal, with its conductivity arising from impurities. AFAIK its status as a nonmetallic element was not sorted out until the 1930s(?) when the physics of semiconductors emerged. OTOH there is this:

"Germanium, Ge, a new nonmetallic[sic] element…" (Winkler 1886)

--- Winkler C (1886), Berichte der Deutschen Chemischen Gesellschaft, vol. 19, pp. 210–211

Arsenic and antimony have a long history of causing difficulties for classification science. The oldest quote I have for As is:

"Arsenic is in the main, however, an acid-forming element and plays the part of a non-metal in its compounds."

--- Schrader FC, Stone RW & Sanford S 1917, Useful minerals of the United States, Bulletin 624, United States Geological Survey, Washington

The oldest quote I have for Sb is:

"Antimony…is of more metallic appearance than arsenic, but, although it has some of the properties of the metals (lustre, electrical and thermal conductivity), in its chemical behaviour it is closely connected with arsenic and phosphorus…Bismuth…has no[sic] non-metallic characters and may be considered as a metal, as it forms no gaseous hydrogen derivative and its oxide has basic characteristics." (Molinari 1920, pp. 426, 792)

--- Molinari E 1920, Treatise on general and industrial inorganic chemistry, 2nd ed., J & A Churchill, London.

Mendeleev, however, regarded both As and Sb to be metals.

I suspect Te may have ended up with an "-ium" suffix due to it appearing to Müller (1783) to form a metallic alloy with gold, as AuTe₂, bearing in mind the limited understanding of time as to the distinction between metals and nonmetals.

Te was described by Mendeleev as forming a transition between metals and nonmetals.

The Pliny link seems reasonably clear as to the distinction between Sb and Pb: "The lees are recognized by being full of lead and they settle to the bottom of the mortars and are thrown away...But above all, it is essential to limit the amount of heat applied to it, so that it may not be turned into lead."

Stibnite can occur with galena (PbS) and that's what appears to be going on.

--- Sandbh (talk) 12:15, 9 January 2024 (UTC)

Let me rephrase my concern so that it's perhaps clearer. :) In metalloid, we have a clear break between elements that are considered metalloids nearly all the time, versus elements that are so considered only sometimes: the most often included among the "sometimes" elements is polonium at 49%. Well, you didn't consider it alongside the others, okay. But my question is: could you get even 49% of chemists to agree that metalloids are nonmetals? Note that I'm not asking "could you get them to agree that metalloids generally have nonmetallic chemical properties and all that". I'm asking "could you get them to agree that metalloids are a subcategory of nonmetals, and not a third category on the border zone that are neither metal nor nonmetal"? My impression of the literature is that you could not. Considering the precedent of metalloid, that suggests that metalloids should not be considered by the article as a normal inclusion into the nonmetals category, but as a sidelined "sometimes", something like how polonium or selenium is treated in Metalloid. So, I would much prefer the number of nonmetal categories to be three, with a caveat that metalloids are sometimes considered nonmetals as a whole, and that since people disagree about where exactly the metalloids end, even authors who think metalloids are an in-between class might annex some (but not all) of usual six into the nonmetals, e.g. Hawkes with metalloids = Ge-As-Se-Te and nonmetals including B and Si. And sure, it would probably be good to know when people stopped calling new metals "semi-metals". :) (At least, Lavoisier in 1789 was happy to list As and Sb among metals, but B as radical boracique is with the nonmetals, and Si is there as an earth alongside what would be Mg, Al, Ca, and Ba.)

I agree that our current understanding of metallicity is better than the past one, but if we are going to give some history, we should at least state how it evolved with greater completeness. No doubt, the understanding of semiconducting behaviour played a large role in figuring out what was going on with Ge and maybe Te.

Pliny seems to think that heating stibnite produces only Pb (and Dioscorides thought the same, according to the link I gave); Sb is not mentioned in this context. Note that in the process he describes, one is not actually trying to get the metal. Indeed, that's exactly what is not wanted: But above all, it is essential to limit the amount of heat applied to it, so that it may not be turned into lead. I think it's reasonable that he'd make a mistake identifying something he considered an unwanted waste product and hence did not really care about. Double sharp (talk) 09:25, 12 January 2024 (UTC)

@Double sharp: Thank you.

I don't know if 49% of chemists would agree metalloids are nonmetals. OTOH, I presume > 49% know that metalloids have a predominately nonmetallic chemistry. Per your suggestion, the article clarifies the "sometimes" nature of metalloids, in the following places:

Places in the nonmetal article re the odd nature of metalloids

Lede A nonmetal is a chemical element that mostly lacks metallic properties. Seventeen [emphasis added] elements are generally considered nonmetals, though some authors recognize more or fewer depending on the properties considered most representative of metallic or nonmetallic character. Elements on the borderline further complicate the situation. usually/always counted as a nonmetal sometimes counted as a nonmetal [i.e. metallloids] 1 Definition and applicable elements There is no precise definition of a nonmetal;[6] any list of such is open to debate and revision.[7] Which elements are included depends on the properties regarded as most representative of nonmetallic or metallic character.[n 3] These fourteen elements are effectively always recognized as nonmetals:[7][8] Hydrogen, Nitrogen, Oxygen, Sulfur Fluorine, Chlorine, Bromine, Iodine Helium, Neon, Argon, Krypton, Xenon, Radon Three more are commonly called nonmetals, but some sources list them as metalloids:[9] Carbon, Phosphorus, Selenium The six most commonly recognized metalloids have relatively low densities and predominantly nonmetallic chemistry and are typically seen as intermediate between metals and nonmetals;[10] they are included in this article for comparison: Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium In the periodic table, to the right of the metals, three to four types of nonmetallic elements can be recognized (proceeding from most to least nonmetallic): the relatively inert noble gases;[110] the notably reactive halogen nonmetals;[111] the mixed reactivity "unclassified nonmetals", a set with no widely used collective name;[n 18] and the generally unreactive[n 20] metalloids,[128] sometimes instead considered a third category distinct from metals and nonmetals. The boundaries between these types are not sharp.[n 21] Carbon, phosphorus, selenium, and iodine border the metalloids and show some metallic character, as does hydrogen. 3 Types The classification of nonmetals can vary, with approaches ranging from as few as two types to as many as seven… In the periodic table, to the right of the metals, three to four types of nonmetallic elements can be recognized (proceeding from most to least nonmetallic)… The greatest discrepancy between authors occurs in the metalloid "frontier territory".[130] Some consider metalloids distinct from both metals and nonmetals, while others classify them as nonmetals.[131] Some categorize certain metalloids as metals (e.g., arsenic and antimony due to their similarities to heavy metals).[132][n 22] Like the elements universally considered "nonmetals", metalloids have relatively low densities, high electronegativity, and similar chemical behavior;[128] they are included in this article for comparative purposes.[n 23] 5 History, background, and taxonomy Metalloids came to be popularly regarded as intermediate elements despite it being known that they have a predominately nonmetallic chemistry. [This sentence recently rearranged by me] Comparison of selected properties The dashed lines around the columns for metalloids signify that the treatment of these elements as a distinct type can vary depending on the author, or classification scheme in use.

I count ten places in which the peculiar treatment of the metalloids is mentioned. The overall emphasis is on the seventeen elements generally recognised as nonmetals, with the six metalloids being mentioned as appropriate.

The metalloid article and nonmetal article work side-by-side. The first has a much narrower focus; the second has a broader focus due to the overlap of the predominately nonmetallic chemistry of the metalloids.

In response to your concerns I've add a paragraph to the Development of types section, explaining the status of B and Si, and what happened to Ge, As, Sn and Te.

How is the article now looking? --- Sandbh (talk) 05:52, 22 January 2024 (UTC)

Nonmetal(s) vs. Nonmetallic (chemical) element(s)

@Sandbh, do you use these terms synonymously?

• nonmetal(s)
• nonmetallic element(s)
• nonmetallic chemical element(s)

When I read this article, I cannot tell whether these are used synonymously or if they are intended to convey some slight distinction. YBG (talk) 05:42, 8 January 2024 (UTC)

@YBG: I use "nonmetallic" in preference to "nonmetal", as the first has more wriggle room i.e. it better accomodates the metalloids. What Oderberg said about nonmetals relates i.e. if something is not a metal than it must be a nonmetal. But I don't want to go to too far down that rabbit hole. --- Sandbh (talk) 07:07, 8 January 2024 (UTC)

@Sandbh: since you prefer nonmetallic, I wonder, where just plain nonmetal is used, does it mean the same thing? Or something slightly different? YBG (talk) 14:19, 8 January 2024 (UTC)

My intention is to use "nonmetallic" when referring to anything including a metalloid, and "nonmetal" otherwise. I haven't however checked for my consistency of usage. --- Sandbh (talk) 11:36, 9 January 2024 (UTC)

I think this is a good rule. Now that I know it, I will try to enforce it when it is needed. After we do a thorough review, it might be good to explicitly state this someplace in the article. YBG (talk) 19:18, 9 January 2024 (UTC)

regarding "Types, metalloids"

AFAIK, semiconducting Sb is only stable as a very thin film (doi:10.1039/D3NR03536K). If we're going to include this sort of thing, then we'd presumably have to also note that B can metallise under such conditions (see borophene). Graphene also counts, though C is placed under unclassified nonmetals. Double sharp (talk) 13:54, 9 January 2024 (UTC)

@Double sharp: Thanks; I've added "Single-layer materials" to the Allotropes hatnote. The metallisation of some of these materials is accommodated in the way the topic sentence in the nonmetal article is composed i.e., "each with distinct physical properties that may vary between metallic and nonmetallic." --- Sandbh (talk) 00:00, 12 January 2024 (UTC)

I agree with this addition, but I do think that the difference should be put in context in "Types, metalloids". The single-layer situation is quite different from the bulk situation: B and C can metallise, whereas Sn, Sb, and Bi either demetallise (fully or partially, considering topological insulators as partial demetallisation) or are theoretically expected to do so. To my mind, this is a rather similar situation to changes under pressure, in which for example Na can demetallise (and then remetallise at extremely high pressures) and Xe can metallise. I think that if you're going to put semiconducting Sb in the main text, then some kind of context is needed to make it clear that unlike semiconducting As, this is not a form that exists in quite usual conditions. At least, if something was only true of graphene and not graphite, I'd feel the need to spell it out specifically, as probably the 2D structure is then related to why it only works in that case.

The way I'd deal with this myself would be to add to the "Allotropes" section a sentence reading "Additional allotropes may occur in more exotic conditions, such as in single-layer materials or under high pressure. The allotropes formed may have unexpected properties: for example, sodium transforms from a metal to a glass-like insulator at ~200 GPa (ref), and oxygen becomes a metallic conductor at 96 GPa (ref). Bulk boron is a semiconductor, but boron nanotubes have metallic properties (ref); contrariwise, single-layer bismuth is a topological insulator, with electrons only free to move along the surface and not the interior (ref). As these properties are quite distinct from bulk behaviour at standard conditions, the remainder of the article will not consider them." And then simply fix the sentence under "Types, metalloids" so that it only lists As and not Sb as having a stable semiconducting form (which is correct under this reasonable assumption). Double sharp (talk) 03:56, 12 January 2024 (UTC)

P.S. regarding high-pressure electrides: more are expected to do it, but only for Li and Na has it actually been seen so far. Double sharp (talk) 09:29, 12 January 2024 (UTC)

@Double sharp: Thank you. The context in "Types, metalloids" is given by the following two sentences: "They [metalloids] are brittle and poor-to-good conductors of heat and electricity. Specifically, boron, silicon, germanium, and tellurium are semiconductors." In this context, it follows that, "Arsenic and antimony have the electronic structures of semimetals, although both have less stable semiconducting forms.^[9]" The semiconducting properties of the metalloids are mentioned due to the strong association of the two concepts. The single layer situation is not relevant here although it is in the Allotropes section. I've nevertheless added a footnote about Sb forming a semiconducting allotrope only in thin film form.

I've adjusted the allotropes section to refer to "less stable" allotropic forms. There is no need for further detail given the hatnote says, "For a more comprehensive list, see Allotropy § Non-metals, and Single-layer materials." --- Sandbh (talk) 06:44, 22 January 2024 (UTC)

@Sandbh: By the logic that the "single layer situation is not relevant here", it seems to me that single-layer allotropes ought not to be included in the "Metalloids" section at all. It is exactly the same kind of thing as including metallic Xe at high pressure under the "noble gas" section: cool, but not really having anything to do with the usual classification. Similarly, it seems to me that allotropes of halogens are also misleading inclusions in the "Allotropes" section without a mention that they are exotic high-pressure phenomena, not something like O₃. To my mind, some kind of context is needed to make it clear what happens at normal conditions and what does not – especially when it gets at the heart at what a nonmetal is. Will anyone call Na a nonmetal? No, but it starts insulating at high pressure. So it seems that a statement about standard conditions is absolutely needed.

P.S. Sn also has an amorphous semiconducting form at low temperature.

P.P.S. The facts that (1) "metalloid" and "semiconductor" are strongly associated concepts and (2) Sb has no bulk semiconducting allotrope suggests something about Sb, especially when that puts it in the same boat as Bi. ;) I wonder if confusion about its allotropes had something to do with antimony's inclusion, perhaps regarding the stability of the black allotrope in bulk, or the existence of the yellow "allotrope" (thought to be Sb₄, but probably is not a real allotrope). Double sharp (talk) 08:33, 23 January 2024 (UTC)

How many types

@Sandbh, we had previously agreed on the wording, but you just now changed “four” to “three to four”. The list following the colon is a list of four items, no more and no less, and so imo the number in the paragraph should be four. One of my previous suggestions had been “four types of elements”, to which you inserted the word “nonmetallic”, but you can remove it if that makes the number four more acceptable. Just please don’t change it back to “3 to 4” without a discussion and agreement to change our previously agreed wording. Thank you! YBG (talk) 06:42, 22 January 2024 (UTC)

@YBG: Thank you. It hadn't occured to me that the adjective "nonmetallic" could in fact accomodate "four types" at the same time as addressing Double sharp's request to refer to three types of nonmetals. I remember the discussion about why I use "nonmetallic". I don't recall having a discussion specificlaly about agreering on either "four" or "three to four" although I know the article has used either expression at varying times.

@Double sharp: Since you expressed a preference for three types of nonmetals, does "four types of nonmetallic elements" works for you?

BTW YBG are there any other remaining concerns you have about the article? Sandbh (talk) 23:19, 22 January 2024 (UTC)

@Double sharp: Does either of these work: four types of nonmetallic elements or else four types of elements? YBG (talk) 04:04, 23 January 2024 (UTC)

@Sandbh: I do not agree with "four types of nonmetallic elements". That outright implies that metalloids are nonmetallic. They are so in some salient chemical properties, but (noting Friend) so are some early transition metals like Mo and W (whose oxides are glass formers, like those of metalloids), and no one would call molybdenum a "nonmetallic element" without a lot of context. And in various other properties, metalloids cluster better with metals. Their thermal conductivity tends to be within the range of metals, and their electronegativity and ionisation energy ranges completely overlap those of metals. And as you already agreed, you could not find a majority of chemists who consider metalloids to be outright nonmetals, so it stands to reason that they should not be emphasised to a greater extent than polonium in metalloid (where you equally well cannot find a majority considering it a metalloid). I would be a lot more comfortable with putting the metalloids as something apart, included for comparison as some of their properties are nonmetallic, but others are not. (Chemically weak metals with a tendency towards amphoterism or worse, like Pb or Mo, may equally well be mentioned briefly.) Double sharp (talk) 08:39, 23 January 2024 (UTC)

@Double sharp. Is a bare four types of elements acceptable? The bullet list itself says metalloids are sometimes instead considered a third category distinct from metals and nonmetals. If that is not strong enough, perhaps we should change “sometimes” to “often”?

Note: the question being addressed in this section is primarily the text of the lead-in to the bullet list. I am trying to avoid the clumsiness of saying “three or four” to introduce a list of four items. YBG (talk) 15:02, 23 January 2024 (UTC)

Scope

List article ledes often include a clear statement of the scope of the list, that is, the inclusion criteria. This is not a list article, but it seems it might benefit from a clear scope statement early in the article. This should at minimum include the exclusion of astatine because its bulk properties are not well attested and inclusion of the metalloids for comparative purposes. Another possible addition would be explaining the use of “nonmetal” vs “nonmetallic element” if we decide to use these terms consistently. I’ve thought a bit about where to put this, and it seems there are three good choices: (1) as the last sentence of the first paragraph (2) as a new paragraph inserted between the first and second (3) as a new paragraph at the end of the top section. There are certainly other choices too. I don’t feel strongly about the location except that the earlier the better and that it should be in the top section. As it currently stands, the scope dt at statement comes much later. Thoughts anyone? YBG (talk) 06:56, 22 January 2024 (UTC)

This could largely be accommodated by showing the start of the article as follows (bold = new):

This article is about a class of up to two dozen or so nonmetallic chemical elements. For the use of the term nonmetal in astronomy, see nonmetal (astrophysics). For nonmetallic substances, see materials science.

A nonmetal is a chemical element that mostly lacks metallic properties. Seventeen elements are generally considered nonmetals, though some authors recognize more or fewer depending on the properties considered most representative of metallic or nonmetallic character. Elements on the borderline, which are sometimes instead referred to as metalloids, further complicate the situation. They are included for comparative purposes, given their predominately nonmetallic^[footnote] chemistry.

Footnote: The term "nonmetallic" generally encompasses nonmetals and metalloids; "nonmetal" generally excludes metalloids. Sandbh (talk) 00:12, 23 January 2024 (UTC)

@YBG: --- Sandbh (talk) 00:13, 23 January 2024 (UTC)

Suggestions

• Hat note: Can we avoid saying both up to and or so? Maybe just up to NNN or else about MMM to NNN?
• Last sentence para 1: Complicating the situation, the borderline metalloids are sometimes considered a category separate from metals and nonmetals.
• New para 1.5: This article includes metalloids for comparative purposes, given their predominately nonmetallic chemistry. The term "nonmetallic" is used to include both nonmetals and metalloids; "nonmetal" excludes metalloids. Astatine is only mentioned briefly due to uncertainty over its bulk properties.

Thoughts? YBG (talk) 04:00, 23 January 2024 (UTC)

Density and electronegativity chart

I’ve added a periodic table to the chart. I’m far from satisfied with the result; suggestions are more than welcome. Things I’ve thought about:

1. Changing the colors scheme
2. Coloring the NG/HN/ON/Md the same in both parts of the chart, a lighter version of the lower right quadrant.
3. Coloring the NG/HN/ON/Md the same in the PT and adding it as a sidebar to the existing four colors in the upper right quadrant
4. Eliminating the element lists in the four-quadrants so it becomes just a legend
5. Removing the PT completely

I added the PT mostly because a color coded PT has much more meaning and context for me than long lists of elements. I suspect this might be so also for the general reader.

I am not wedded to this idea; if it seems distracting or cluttered and you can’t figure out a way to improve it, feel free to revert it completely. YBG (talk) 15:51, 23 January 2024 (UTC)