Nomenclature
CAS number: 7440-41-7
Glucinium.
Description and references
Be; at. wt 9.012182; at. no. 4; valence 2.
Group IIA (2). Alkaline earth metal. Estimated abundance in earth's
crust 2 to 6 ppm. Natural isotopes (mass number): 9 (100%); known
artificial radioactive isotopes: 6-8; 10-12. Oxide discovered by
Vauquelin in 1797; free metal isolated by W"ohler and Bussy in 1828.
Produced industrially from beryl (3BeO.Al2O3.6SiO2) and bertrandite (4BeO.2SiO2.H2O); also found
in phenacite (Be2SiO4), chrysoberyl (BeO.Al2O3). Precious forms of beryl:
emerald, aquamarine. Reviews of beryllium and its compounds: Kjellgren, “Beryllium”
in Rare Metals Handbook, C. A.
Hampel, Ed. (Reinhold, New York, 1954) pp 31-55; D. A. Everest, Chemistry of Beryllium (Elsevier, New
York, 1964) 151 pp. Review of properties and use: N. P. Pinto, J.
Greenspan, “Beryllium” in Modern Materials vol. 6, B. W. Gonser, Ed. (Academic Press, New York,
1968) pp 319-372; D. A. Everest, “Beryllium” in Comprehensive Inorganic Chemistry, J. C. Bailar, Jr. et al., Eds. (Pergamon Press, Oxford, 1973) pp 531-590; A.
J. Stonehouse et al., in Kirk-Othmer
Encyclopedia of Chemical Technology vol. 4 (Wiley-Interscience,
New York, 4th ed., 1992) pp 126-146; A. J. Stonehouse, M. N. Emly, ibid. 147-153. Review of carcinogenic risk of beryllium and
its compds: IARC Monographs 1, 17-28 (1972); ibid. 23, 143-204 (1980);
of toxicology and human exposure: Toxicological
Profile for Beryllium (PB2003-100135, 2002) 290 pp.; of
immunotoxicology: A. L. Reeves, O. P. Preuss in Immunotoxicology and Immunopharmacology, J. H. Dean et al., Eds. (Raven Press, New York, 1985) pp 441-455; of human
and environmental toxicology: WHO, Environ.
Health Criter. 106, 1-210 (1990).
Properties
Gray, brittle metal; close-packed hexagonal structure;
anisotropic; high permeability to X-rays; can serve as a neutron source
through either (α,n) or (n,2n) reactions.
Lightest of all solid and chemically-stable substances. Displays
excellent electrical and thermal conductivities. Poisonous, flammable. mp 1287°. bp 2500° (extrapolated). d 1.8477. Heat capacity at constant pressure (30°) 0.437
cal/g/°C: Walker et al., J. Chem.
Eng. Data 7, 595 (1962). Latent heat of fusion:
3.5 kcal/ mole. Brinell hardness: 60-125. Chemical properties
similar to aluminum; metal resistant to attack by acid due to the
formation of a thin oxide film. E° (aq) Be/Be2+ 1.85 V
(calc.). Finely divided or amalgamated metal reacts with HCl, dil
H2SO4 and dil HNO3; attacked by strong
bases with evolution of H2.Caution
Overexposure to beryllium and beryllium
compounds has been associated with acute and chronic toxicity. Toxicity
due to chronic inhalation is called “berylliosis” and appears after
a latent period as an immunologically mediated, progressive, systemic
disease leading to the formation of a characteristic granulomatous
lesion. Potential symptoms of overexposure are anorexia, weight loss,
weakness, chest pains, cough, clubbing of fingers, cyanosis, pulmonary
insufficiency; direct contact may cause eye irritation. Dermal exposure
may cause acute contact dermatitis; chronic dermal exposure may cause
granulomatous skin ulceration. See Patty's Industrial Hygiene and Toxicology vol. 2C, G. D. Clayton, F. E. Clayton, Eds. (John Wiley & Sons, Inc.,
New York, 4th ed., 1994) pp 1930-1948; NIOSH
Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140,
1997) p 28. Beryllium and beryllium compounds are listed as known
human carcinogens: Report on Carcinogens,
Eleventh Edition (PB2005-104914, 2004) p III-32.Use
Source of neutrons when bombarded with alpha particles
according to the equation
94Be +
42He →
612C +
10n. This yields about 30 neutrons per million alpha particles. Also
as neutron reflector and neutron moderator in nuclear reactors. In
beryllium copper and beryllium aluminum alloys (by direct reduction
of beryllium oxide with carbon in the presence of Cu or Al). In aerospace,
aircraft and satellite structures; x-ray transmission windows; missile
parts; nuclear weapons; fuel containers; precision instruments; rocket
propellants; navigational systems; heat shields; and mirrors. For
fiber optics and cellular network communications systems.