Beryllium
Atomic Number: 4
Symbol: Be
Atomic Weight: 9.01218
Discovery: 1798, Louis-Nicholas Vauquelin (France)
Electron Configuration: [He]2s2
Other Names: Glucinium or Glucinum
Word Origin: Greek: beryllos, beryl; Greek: glykys, sweet (note that beryllium is toxic)
Properties: Beryllium has a melting point of 127+/-5°C, boiling point of 2970°C, specific gravity of 1.848 (20°C), and valence of 2. The metal is steel-gray in color, very light, with one of the highest melting points of the light metals. Its modulus of elasticity is a third higher than that of steel. Beryllium has high thermal conductivity, is nonmagnetic, and resists attack by concentrated nitric acid. Beryllium resists oxidation in air at ordinary temperatures. The metal has a high permeability to x-radiation. When bombarded by alpha particles, it yields neutrons in the ratio of approximately 30 million neutrons per million alpha particles. Beryllium and its compounds are toxic and should not be tasted to verify the metal's sweetness.
Uses: Precious forms of beryl include aquamarine, morganite, and emerald. Beryllium is used as an alloying agent in producing beryllium copper, which is used for springs, electrical contacts, nonsparking tools, and spot-welding electrodes. It is used in many structural components of the space shuttle and other aerospace craft. Beryllium foil is used in x-ray lithography for making integrated circuits. It is used as a reflector or moderator in nuclear reactions. Beryllium is used in gyroscopes and computer parts. The oxide has a very high melting point and is used in ceramics and nuclear applications.
Sources: Beryllium is found in approximately 30 mineral species, including beryl (3BeO Al2O3 6SiO2), bertrandite (4BeO 2SiO2 H2O), chrysoberyl, and phenacite. The metal may be prepared by reducing beryllium fluoride with magnesium metal.
Element Classification: Alkaline-earth Metal
Density (g/cc): 1.848
Appearance: hard, brittle, steel-gray metal
Atomic Radius (pm): 112
Atomic Volume (cc/mol): 5.0
Covalent Radius (pm): 90
Ionic Radius: 35 (+2e)
Specific Heat (@20°C J/g mol): 1.824
Fusion Heat (kJ/mol): 12.21
Evaporation Heat (kJ/mol): 309
Debye Temperature (K): 1000.00
Pauling Negativity Number: 1.57
First Ionizing Energy (kJ/mol): 898.8
Oxidation States: 2
Lattice Structure:Hexagonal
Lattice Constant (Å): 2.290
Lattice C/A Ratio: 1.567
References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Lange's Handbook of Chemistry (1952), CRC Handbook of Chemistry & Physics (18th Ed.)
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