Beryllium: the essentials
Beryllium is a Group 2 (IIA) element. It is a metal and has a high melting point. At ordinary temperatures, beryllium resists oxidation in air. Beryllium compounds are very toxic. Its ability to scratch glass is probably due to the formation of a thin layer of the oxide. Aquamarine and emerald are precious forms of the mineral beryl, [Be3Al2(SiO3)6].
Its chemistry is dominated by its tendency to lose an electron to form Be2+. As this ion is so small it is highly polarising, to the extent that its compounds are rather covalent. Its small size means that its complexes tend to be tetrahedral rahter than octahedral.
Beryllium: historical information
Emeralds and beryl were both known to early Egyptians but it was not realised until the end of the 18th century that they are the same mineral, now called beryllium aluminium silicate: [Be3Al2(SiO3)6]. The element was recognised by M.-L. Vauquelin in 1798 in beryl and emeralds. The metal was isolated much later on in 1828 by Friederich Wöhler (and independently by A.-A.B. Bussy) by the action of potassium on BeCl2 in a platinum crucible.
Beryllium around us Read more »
Beryllium has no biological role. In fact, compounds containing beryllium are poisonous.
Beryllium is found in a number of minerals. The most important minerals are beryl, [Be3Al2(SiO3)6], which is often found as hexagonal prisms, and bertrandite [4BeO.2SiO2.H2O]. Aquamarine and emerald are precious forms of beryl.
|Location||ppb by weight||ppb by atoms||Links|
|Human||0.4 ppb by weight||0.3 atoms relative to C = 1000000|
Physical properties Read more »
Heat properties Read more »
- Melting point: 1560 [1287 °C (2349 °F)] K
- Boiling point: 2742 [2469 °C (4476 °F)] K
- Enthalpy of fusion: |203| kJ mol-1
Crystal structure Read more »
The solid state structure of beryllium is: hcp (hexagonal close-packed).
Beryllium: orbital properties Read more »
Beryllium atoms have 4 electrons and the shell structure is 2.2. The ground state electronic configuration of neutral Beryllium is [He].2s2 and the term symbol of Beryllium is 1S0.
- Pauling electronegativity: 1.57 (Pauling units)
- First ionisation energy: 899.5 kJ mol‑1
- Second ionisation energy: 1757.1 kJ mol‑1
Isolation: beryllium metal is available commercially and so would never normally be made in the laboratory. Its extraction from ores is complex. The mineral beryl, [Be3Al2(SiO3)6] is the most important source of beryllium. It is roasted with sodimu hexafluorosilicate, Na2SiF6, at 700°C to form beryllium fluoride. This is water soluble and the beryllium may be precipitated as the hydroxide Be(OH)2 by adjustment of the pH to 12.
Pure beryllium may be obtained by electrolysis of molten BeCl2 containing some NaCl. The salt is added since the molten BeCl2 conducts very poorly. Another method involves the reduction of beryllium fluoride with magnesium at 1300°C.
BeF2 + Mg → MgF2 + Be
Beryllium isotopes Read more »
|9Be||9.012 182 1(4)||100||3/2||-1.1779|