| Beryllium - Be
CAS: CAS: 7440-41-7 Description: Strong, hard, gray-white metal; lightest rigid metal Classification: Alkaline earth metal Date of Discovery: 1798 Discoverer: Fredrich Wohler Name Origin: Greek beryllos, the mineral "beryl" Alternate Names: Glucinium or Glucinum, Greek glykys, sweet |
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Atomic Number: 4
Number of Neutrons: 5 Atomic Mass: 9.012182(3) amu Melting Point: 1287 °C Boiling Point: 2471 °C Density (293 K): 1.8477 g/cm3 Atomic volume: 5.0 cm3/mol Electrical resistivity: 0.313 10-6/cm 
Thermal conductivity: 2.00 W/cmK Enthalpy of atomization: 326.35 kJ/mol Enthalpy of vaporization: 292.40 kJ/mol Enthalpy of fusion: 12.20 kJ/mol Specific heat capacity: 1.82 J/gK |
Energy levels: 2-2
Electron configuration: [He]2s2 Crystal Structure: Hexagonal Atomic radius: 1.40 Å Covalent radius: 0.90 Å Oxidation States: +2 Electronegativity, Pauling: 1.57 Electron affinity: not stable First ionization energy: 9.322 eV 2nd ionization energy: 18.211 eV 3rd ionization energy: 153.893 eV Polarizability: 5.60 10-24cm3 |
| Isotope | Natural Abundance | Atomic Mass | Half-life | Decay Mode | Spin |
| 6Be | 6.01973 | 5.0 x 10-21 s | 2p,  |
0+ | |
| 7Be | 7.016929 | 53.28 d | EC | 3/2- | |
| 8Be | 8.0053051 |  7 x 10-17 s |
2- |
0+ | |
| 9Be | 100. | 9.012182 | Stable | 3/2- | |
| 10Be | 10.013534 | 1.52 x 106 y |  - |
0+ | |
| 11Be | 11.02166 | 13.8 s | -, - |
1/2+ | |
| 12Be | 12.02692 | 24 ms | - |
0+ | |
| 14Be | 14.0428 | 4 ms | - |
0+ | |
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Discovered as the oxide by Vauquelin in beryl and in emeralds in 1798. The metal was isolated in 1828 by Wobler and by Bussy independently by the action of potassium on beryllium chloride. Beryllium is found in some 30 mineral species, the most important of which are bertrandite (4BeO · 2SiO2 · H2O), beryl (3BeO · Al2O2 · 6SiO2), chrysoberyl (BeAl2O4), and phenakite (Be2SiO2). Aquamarine and emerald are precious forms of beryl. Beryl and bertrandite are the most important commercial sources of the element and its compounds. Most of the metal is now prepared by reducing beryllium fluoride with magnesium metal. Beryllium metal did not become readily available to industry until 1957. The metal, steel gray in color, has many desirable properties. It is one of the lightest of all metals, and has one of the highest melting points of the light metals. Its modulus of elasticity is about one third greater than that of steel. It resists attack by concentrated nitric acid, has excellent thermal conductivity, and is nonmagnetic. It has a high permeability to X-rays, and when bombarded by alpha particles, as from radium or polonium, neutrons are produced in the ratio of about 30 neutrons/million alpha particles. At ordinary temperatures beryllium resists oxidation in air, although its ability to scratch glass is probably due to the formation of a thin layer of the oxide. Beryllium is used as an alloying agent in producing beryllium copper which is extensively used for springs, electrical contacts, spot-welding electrodes, and nonsparking tools. It has found application as a structural material for high-speed aircraft, missiles, spacecraft, and communication satellites. It is being used in the windshield , brake discs, support beams, and other structural components of the space shuttle. Because beryllium is relatively transparent to X-rays, ultra-thin Be-foil is finding use in X-ray lithography for reproduction of microminiature integrated circuits. Natural beryllium is made of 9Be and is stable. Eight other radioactive isotopes are known. Beryllium is used in nuclear reactors as a reflector or moderator for it has a low thermal neutron absorption cross section. It is used in gyroscopes, computerparts and instruments where flatness and stiffness, and dimensional stability are required. The oxide has a very high melting point and is also used in nuclear work and ceramic applications. Beryllium and its salts are toxic and should be handled with the greatest of care. Beryllium and its compounds should not be tasted to verify the sweetish nature of beryllium (as did early experimenters). The metal, its alloys, and its salts can be handled safely if certain work codes are observed, but no attempt should be made to work with beryllium before becoming familiar with proper safeguards.
LINKS: AMM Online - Beryllium Profile Beryllium Hazards Beryllium Homepage - University of Wuerzburg DOE Training Reference for Beryllium Lisa's Beryllium Page Minerals Containing Beryllium OSHA Chemical Sampling Information Return
Sources for the information on this website include: Lide, David R., ed. CRC Handbook of Chemistry and Physics, 78th Ed., 1997-1998. |
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