Beryllium

Beryllium is in group 2 of the periodic table, so it is an alkaline earth metal. It is grayish (slightly gray) in color. It has an atomic number of 4 and is symbolized by the letters Be. It is toxic and should not be handled without proper training.

Beryllium, ₀₀Be

Beryllium
Pronunciation	/bəˈrɪliəm/ ​(bə-RIL-ee-əm)
Appearance	white-gray metallic
Standard atomic weight Ar°(Be)
	9.0121831(5)[1]
Beryllium in the periodic table
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson – ↑ Be ↓ Mg lithium ← beryllium → boron
Group	group 2 (alkaline earth metals)
Period	period 2
Block	s-block
Electron configuration	[He] 2s2
Electrons per shell	2, 2
Physical properties
Phase at STP	solid
Melting point	1560 K ​(1287 °C, ​2349 °F)
Boiling point	2742 K ​(2469 °C, ​4476 °F)
Density (near r.t.)	1.85 g/cm3
when liquid (at m.p.)	1.690 g/cm3
Critical point	5205 K,  MPa (extrapolated)
Heat of fusion	12.2 kJ/mol
Heat of vaporization	292 kJ/mol
Molar heat capacity	16.443 J/(mol·K)
Vapor pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 1462 1608 1791 2023 2327 2742
Atomic properties
Oxidation states	0,[2] +1,[3] +2 (an amphoteric oxide)
Electronegativity	Pauling scale: 1.57
Ionization energies	1st: 899.5 kJ/mol 2nd: 1757.1 kJ/mol 3rd: 14,848.7 kJ/mol (more)
Atomic radius	empirical: 112 pm
Covalent radius	96±3 pm
Van der Waals radius	153 pm
Spectral lines of beryllium
Other properties
Natural occurrence	primordial
Crystal structure	​hexagonal close-packed (hcp)
Speed of sound thin rod	12,890 m/s (at r.t.)[4]
Thermal expansion	11.3 µm/(m⋅K) (at 25 °C)
Thermal conductivity	200 W/(m⋅K)
Electrical resistivity	36 nΩ⋅m (at 20 °C)
Magnetic ordering	diamagnetic
Molar magnetic susceptibility	−9.0·10−6 cm3/mol[5]
Young's modulus	287 GPa
Shear modulus	132 GPa
Bulk modulus	130 GPa
Poisson ratio	0.032
Mohs hardness	5.5
Vickers hardness	1670 MPa
Brinell hardness	590–1320 MPa
CAS Number	7440-41-7
History
Discovery	Louis Nicolas Vauquelin (1798)
First isolation	Friedrich Wöhler & Antoine Bussy (1828)
Isotopes of beryllium v e
Main isotopes[6] Decay abun­dance half-life (t1/2) mode pro­duct 7Be trace 53.22 d ε 7Li 8Be 0% (extinct) 81.9 as α 4He 9Be 100% stable 10Be trace 1.387×106 y β− 10B
Category: Beryllium view talk edit | references

Beryllium has 4 electrons, 4 protons, and 5 neutrons.

Beryllium has one of the highest melting points of the light metals: 1560 K (1287 °C). It is added to other metals to make stronger alloys. Beryllium-copper alloy is used in tools because it does not make sparks.

At standard temperature and pressure, beryllium resists oxidation when exposed to oxygen.

Beryllium is best known for the chemical compounds it forms. Beryllium combines with aluminium, silicon and oxygen to make a mineral called beryl. Emerald and aquamarine are two varieties of beryl which are used as gemstones in jewelry.

Since it has a very high stiffness to weight ratio, beryllium is used to make the diaphragms in some high-end speakers.

Uses

Beryllium is used to make jet aircrafts, guided missiles, spacecraft, and satellites, including the James Webb telescope.^[7][8] Beryllium can reflect neutrons, and thin foils of beryllium are sometimes used in nuclear weapons as the outer layer of the plutonium pits.^[9] Beryllium is also used in fuel rods for CANDU reactors. Beryllium is used to make many dental alloys.^[7][8]

Rarity

It is a relatively rare element in the universe. It usually occurs when larger atomic nuclei have split up. In stars, beryllium is depleted because it is fused and builds larger elements.

Related pages

• Periodic table
• List of common elements