Nihonium

Nihonium, ₁₁₃Nh

Nihonium
Pronunciation	/nɪˈhoʊniəm/ ​(nih-HOH-nee-əm)
Mass number	[286]
Nihonium in the periodic table
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Tl ↑ Nh ↓ — copernicium ← nihonium → flerovium
Atomic number (Z)	113
Group	group 13 (boron group)
Period	period 7
Block	p-block
Electron configuration	[Rn] 5f14 6d10 7s2 7p1 (predicted)
Electrons per shell	2, 8, 18, 32, 32, 18, 3 (predicted)
Physical properties
Phase at STP	solid (predicted)
Melting point	700 K ​(430 °C, ​810 °F) (predicted)
Boiling point	1430 K ​(1130 °C, ​2070 °F) (predicted)
Density (near r.t.)	16 g/cm3 (predicted)
Heat of fusion	7.61 kJ/mol (extrapolated)
Heat of vaporization	130 kJ/mol (predicted)
Atomic properties
Oxidation states	common: (none)
Ionization energies	1st: 704.9 kJ/mol (predicted) 2nd: 2240 kJ/mol (predicted) 3rd: 3020 kJ/mol (predicted) (more)
Atomic radius	empirical: 170 pm (predicted)
Covalent radius	172–180 pm (extrapolated)
Other properties
Natural occurrence	synthetic
Crystal structure	​hexagonal close-packed (hcp) (predicted)
CAS Number	54084-70-7
History
Naming	After Japan (Nihon in Japanese)
Discovery	Riken (Japan, first undisputed claim 2004) JINR (Russia) and Livermore (US, first announcement 2003)
Isotopes of nihonium
Main isotopes Decay abun­dance half-life (t1/2) mode pro­duct 278Nh synth 2.0 ms α 274Rg 282Nh synth 61 ms α 278Rg 283Nh synth 123 ms α 279Rg 284Nh synth 0.90 s α 280Rg ε 284Cn 285Nh synth 2.1 s α 281Rg SF – 286Nh synth 9.5 s α 282Rg 287Nh synth 5.5 s? α 283Rg 290Nh synth 2 s? α 286Rg

Ununtrium (Template:PronEng or /əˈnʌntriəm/) is the temporary name of a synthetic element in the periodic table that has the temporary symbol Uut and has the atomic number 113.

It has been synthesised both directly in "cold" and "warm" fusion reactions. It was first observed in the decay of ununpentium. Only eight atoms of ununtrium have been observed to date. Following periodic trends it is expected to be a soft, silvery metal.

Discovery Profile

The first report of ununtrium was in August 2003 when it was identified as a decay product of kuuuuuuuuuuu=03Og01>"Experiments on the synthesis of element 115 in the reaction ²⁴³Am(⁴⁸Ca,xn)^291-x115", Oganessian et al., JINR Preprints, 2003. Retrieved on 2008-03-03</ref>

$\,_{20}^{48}\mathrm {Ca} +\,_{95}^{243}\mathrm {Am} \to \,^{288,287}\mathrm {Uup} \to \,^{284,283}\mathrm {Uut} \to \$

On July 23, 2004, a team of Japanese scientists at RIKEN detected a single atom of ²⁷⁸Uut using the cold fusion reaction between Bismuth-209 and zinc-70. They published their results on September 28, 2004.

$\,_{30}^{70}\mathrm {Zn} +\,_{83}^{209}\mathrm {Bi} \to \,_{113}^{279}\mathrm {Uut} ^{*}\to \,_{113}^{278}\mathrm {Uut} +\,_{0}^{1}\mathrm {n}$

Support for their claim appeared in 2004 when scientists at the Institute of Modern Physics (IMP) identified ²⁶⁶Bh as decaying with identical properties to their single event (see bohrium).

The RIKEN team produced a further atom on April 2, 2005, although the decay data was different from the first chain, and may be due to the formation of a meta-stable isomer.

The Dubna-Livermore collaboration has strengthened their claim for the discovery of ununtrium by conducting chemical experiments on the decay daughter ²⁶⁸Db. In experiments in Jun 2004 and Dec 2005, the Dubnium isotope was successfully identified by milking the Db fraction and measuring any SF activities. Both the half-life and decay mode were confirmed for the proposed ²⁶⁸Db which lends support to the assignment of Z=115 and Z=113 to the parent and daughter nuclei.

Theoretical estimates of alpha-decay half-lives of alpha-decay chains from element 113 are in good agreement with the experimental data.

Naming

Current names

The element with Z=113 is historically known as eka-thallium. Ununtrium (Uut) is a temporary IUPAC systematic element name. Research scientists usually refer to the element simply as element 113 (E113).

Proposed names by claimants

Claims to the discovery of element 113 have been put forward by Dmitriev of the Dubna team and Morita of the RIKEN team. The JWP will decide to whom the right to suggest a name will be given. The IUPAC have the final say on the official adoption of a name. The table below gives the names that the teams above have suggested and which can be verified by press interviews.

Group	Proposed Name	Proposed Symbol	Derivation
RIKEN	Japonium	Jp	Japan - country of group claimants
RIKEN	Rikenium	Rk	RIKEN - institute of group claimants

Disallowed names

According to IUPAC rules, names used for previous elements that have ultimately not been adopted are not allowed to be proposed for future use. The table below summarises those names which are probably not allowed to be proposed by the claimant laboratories under the rules.

Group Claim Affected	Disallowed Name	Disallowed Symbol	Reason
RIKEN	Nipponium	Np	Used for claimed discovery of element 43
Dubna	Russium	Rs	Used for claimed discovery of element 43

Plausible names

Many speculative names appear in popular literature. The table below lists these names in the case where they obey IUPAC rules and are plausible with regard to the claimant laboratories. Rumoured suggestions (*) linked to the claimant laboratories are also included.

Group Link	Suggested Name	Suggested Synbol	Derivation	Comments
RIKEN	Nihonium *	Nh	Nihon - Japanese for Japan	more appropriate, a really local name
Dubna	Becquerelium *	Bq	Henri Becquerel - discoverer of radioactivity	Dubna team suggested the name for element 110

Electronic structure

Ununtrium is element 113 in the Periodic Table. The two forms of the projected electronic structure are:

Bohr model: 2, 8, 18, 32, 32, 18, 3

Quantum mechanical model: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰ 4p⁶5s²4d¹⁰5p⁶6s²4f¹⁴5d¹⁰ 6p⁶7s²5f¹⁴6d¹⁰7p¹

Extrapolated chemical properties of eka-thallium

Oxidation states

Element 113 is projected to be the first member of the 7p series of non-metals and the heaviest member of group 13 (IIIA) in the Periodic Table, below thallium. Each of the members of this group show the group oxidation state of +III. However, thallium has a tendency to form only a stable +I state due to the "inert pair effect", explained by the relativistic stabilisation of the 7s-orbitals, resulting in a higher ionisation potential and weaker tendency to participate in bonding.

Chemistry

Element 113 should portray eka-thallium chemical properties and should therefore from a monoxide, Uut₂O, and monohalides, UutF, UutCl, UUtBr and UutI. If the +III state is accessible, it is likely that it is only possible in the oxide, Uut₂O₃, and fluoride, UutF₃.

History of synthesis of isotopes by cold fusion

²⁰⁹Bi(⁷⁰Zn,xn)^279-x113 (x=1)

The synthesis of element 113 was first attempted in 1998 by the team at GSI using the above cold fusion reaction. In two separate runs, they were unable to detect any atoms and calculated a cross section limit of 900 fb. They repeated the experiment in 2003 and lowered the limit further to 400 fb. In late 2003, the emerging team at RIKEN using their efficient apparatus GARIS attempted the reaction and reached a limit of 140 fb. In December 2003-August 2004, they resulted to 'brute force' and performed an eight-month-long irradiation in which they increased the sensitivity to 51 fb. They were able to detect a single atom of ²⁷⁸113. They repeated the reaction in several runs in 2005 and were able to synthesise a second atom. They calculated a record-low 31 fb for the cross section for the 2 atoms.

History of synthesis of isotopes by hot fusion

²³⁷Np(⁴⁸Ca,xn)^285-x113 (x=3)

In June 2006, the Dubna-Livermore team synthesised ununtrium directly in the "warm" fusion reaction between neptunium-237 and calcium-48 nuclei. Two atoms of ²⁸²Uut were detected with a cross section of 900 fb.

Chronology of isotope discovery

Isotope	Year discovered	discovery reaction
278Uut	2004	209Bi(70Zn,n)
279Uut	unknown
280Uut	unknown
281Uut	unknown
282Uut	2006	237Np(48Ca,3n)
283Uut	2003	243Am(48Ca,4n)
284Uut	2003	243Am(48Ca,3n)

Yields of isotopes

Cold fusion

The table below provides cross-sections and excitation energies for cold fusion reactions producing ununtrium isotopes directly. Data in bold represents maxima derived from excitation function measurements. + represents an observed exit channel.

Projectile	Target	CN	1n	2n	3n
70Zn	209Bi	279Uut	31 fb

Hot Fusion

The table below provides cross-sections and excitation energies for hot fusion reactions producing ununtrium isotopes directly. Data in bold represents maxima derived from excitation function measurements. + represents an observed exit channel.

Projectile	Target	CN	3n	4n	5n
48Ca	237Np	285Uut	0.9pb , 39.1 MeV

See also

• Isotopes of ununtrium
• Island of stability

External links

• WebElements.com - Uut
• Uut and Uup Add Their Atomic Mass to Periodic Table
• Apsidium - Ununtrium
• Discovery of Elements 113 and 115
• Superheavy elements