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4 Be 9.012182(3)

Beryllium

Alkaline earth metal
Symbol Be
Atomic Number 4
Atomic Weight 9.012182(3)
CAS Registry ID 7440-41-7
Group Name Alkaline earth metal
Period Number 2
Block s-block
State at STP Solid

Description

Sample of Beryllium ⌕ Enlarge Image

Beryllium is an alkaline earth metal with an atomic weight of 9.012182. It has a melting point of 2349 °F, and a boiling point of 4476 °F. Beryllium is steel grey in color, resists oxidation at normal temperatures, is permeable to x-ray radiation, and is 1/3 more elastic than steel. Current uses of beryllium include: as an allow with nickel to create tools that do not spark, as an alloy with copper to create parts for computers and gyroscopes, in ceramics, and as a component in allow mixtures for high performance aircraft.

Isolation

Beryllium metal is isolated on a commercial scale and so it is hardly ever isolated using laboratory metals. There are three frequent methods of isolating beryllium.

Beryllium ⌕ Enlarge Image

The first method of beryllium isolation involves extracting beryllium from the ore beryl which has the chemical formula of Be3Al2(SiO3)6. Beryl is heated with sodium hexaflourosilicate at a temperature of 1292 °F to produce beryllium fluoride. The beryllium fluoride is water soluble and so the next step involves isolating beryllium out through a precipitation process. The beryllium fluoride is mixed with water to create a solution, and by increasing the pH of the solution to 12 the beryllium can be precipitated out as beryllium hydroxide. The second step of beryllium isolation involves using electrolysis of molten beryllium chloride that has been mixed with sodium chloride; the sodium chloride addition is necessary for electrolysis because beryllium does not conduct electricity well. The third isolation beryllium procedure involves heating beryllium fluoride with magnesium metal to 2372 °F; the end products of this isolation procedure yield magnesium fluoride and pure beryllium. The isolations procedures used depend on the tools and material at hand, and how much of a beryllium yield is needed.

General

NameBeryllium
SymbolBe
Number4
Chemical seriesAlkaline earth metal
Group2
Period2
Blocks
Appearancewhite-gray metallic
Standard atomic weight9.012182(3) g·mol⁻¹
Electron configuration1s2 2s2
Electrons per shell2, 2

Atomic Properties

Crystal structurehexagonal
Oxidation states2 (amphoteric oxide)
Electronegativity1.57 (Pauling scale)
Ionization energies1st: 899.5 kJ·mol−1
2nd: 1757.1 kJ·mol−1
3rd: 14848.7 kJ·mol−1
Atomic radius105 pm
Atomic radius (calc.)112 pm
Covalent radius90 pm
Van der Waals radius

Physical Properties

Phasesolid
Density (near r.t.)1.85 g·cm−3
Liquid density at m.p.1.690 g·cm−3
Melting point1560 K (1287 °C, 2349 °F)
Boiling point2742 K (2469 °C, 4476 °F)
Critical point
Heat of fusion7.895 kJ·mol−1
Heat of vaporization297 kJ·mol−1
Heat capacity(25 °C) 16.443 J·mol−1·K−1

Miscellaneous

Magnetic orderingdiamagnetic
Electrical resistivity
Thermal conductivity(300 K) 200 W·m−1·K−1
Thermal expansion(25 °C) 11.3 µm·m−1·K−1
Speed of sound (thin rod)(20 °C) 35.6 n m/s
Young's modulus(r.t.) 12870 m·s−1
Shear modulus132 GPa
Bulk modulus130 GPa
Poisson ratio0.032
Mohs hardness5.5
Vickers hardness1670 MPa
Brinell hardness600 MPa