Beryllium

Beryllium is a chemical element in the periodic table that has the symbol Be and atomic number 4. Beryllium is an alkaline earth metal that is steel gray in color and is used to make watch springs.

General Properties Name Beryllium Symbol Be Group Alkaline earth metal Atomic number 4 Atomic mass 9.01218 amu Density at 293 K 1.848 g/cm3 Electron configuration [He]2s2 Oxidation states 2 (amphoteric) Crystal Structure Hexagonal Physical Properties at STP State of matter Solid Melting point 1551.15 K (1278°C) Boiling point 3243.15 K (2970°C) Heat of vaporization 292.40 kJ/mol Heat of fusion 12.20 kJ/mol Specific heat 1.82 J/g*K Other Properties Shells 2,2 Electronegativity 1.57 Covalent radius 0.90 Å Atomic radius 1.40 Å Atomic volume 5.0 cm3/mol 1st ionization potential 9.322 eV 2nd ionization potential 18.211 eV 3rd ionization potential 153.893 eV Electrical conductivity 0.313 106/cm ohm Thermal conductivity 2.00 W/cmK Half-Lifes of Isotopes 7Be t1/2 53.3 days 9Be t1/2 stable 10Be t1/2 1.51 ± 0.06 x106 y

Notable Characteristics
Beryllium has one of the highest melting points of the light metals. The modulus of elasticity of this light metal is approximately 1/3 greater than steel. This element has excellent thermal conductivity, is nonmagnetic and resists attack by concentrated nitric acid. This metal is highly permeable to X-rays and neutrons are liberated when it is hit by alpha particles, as from radium or polonium (about 30 neutrons/million alpha particles). At standard temperatures and pressures beryllium resists oxidation when exposed to air (although its ability to scratch glass is probably due to the formation of a thin layer of the oxide).

Uses
Beryllium is used as an alloying agent in the production of beryllium copper, which is used to make spot-welding electrodes, springs, non-sparking tools and electrical contacts. In the aerospace industry, it is used as a structural material in high-speed aircraft, missiles, space vehicles and communication satellites. In the field of X-ray lithography beryllium is being used for the reproduction of microscopic integrated circuits. Because this metal has a low thermal neutron absorption cross section, the nuclear power industry uses this metal in nuclear reactors as a neutron reflector and moderator. Other uses of beryllium occur in the making of gyroscopes, various computer equipment, and instruments where light-weight, rigidity and dimensional stability are needed. Beryllium oxide has a very high melting point which is useful for several other applications that require this property.

History
(Gr. beryllos, beryl) At one time Beryllium was referred to as glucinium (Gr. glykys, sweet), due to the sweet taste of its salts. This element was discovered by Vauquelin in 1798 as the oxide in beryl and in emeralds. Wohler and Bussy independently isolatated the metal in 1828 by reacting potassium on beryllium chloride.

Sources
Beryllium is found in 30 different minerals, the most important of which are bertrandite, beryl, chrysoberyl, and phenacite. Precious forms of beryl are Aquamarine and emerald. The most important commercial sources of Beryllium and its compounds are beryl and bertrandite. Currently, most production of this metal is accomplished by reducing beryllium fluoride with magnesium metal. Beryllium metal did not become readily available until 1957.

Isotopes
Beryllium has only one isotope, ⁹Be, on earth. Cosmogenic Beryllium (¹⁰Be) is produced in the atmosphere by cosmic ray spallation of oxygen and nitrogen. Because beryllium tends to exist in solution at pH levels less than about 5.5 (and most rainwater has a pH less than 5), it will enter into solution and be transported to the Earth's surface via rainwater. As the precipitation quickly becomes more alkaline, Be drops out of solution. Cosmogenic ¹⁰Be thereby accumulates at the soil surface, where its long half-life (1.5 Ma) permits a long residence time before decaying to ⁹Be. ¹⁰Be and its daughter products have been used to examine soil erosion, soil formation from regolith, and the development of lateritic soils.

Precautions
Beryllium and its salts are toxic.
Early researchers tasted beryllium and its various compounds for sweetness in order to verify its presence. Modern diagnostic equipment no longer necessitates this highly risky procedure and no attempt should be made to ingest this substance. Beryllium and its compounds should be handled with great care and special precautions must be taken when carrying out any activity which could result in the release of beryllium dust.

This substance can be handled safely if certain procedures are followed. No attempt should be made to work with beryllium before familiarization with correct handling procedures.

References:
Los Alamos National Laboratory - Beryllium
EnvironmentalChemistry.com - Beryllium

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See: Periodic Table