Template:Infobox beryllium

Beryllium,  ₄Be

General properties
Name, symbol	beryllium, Be
Appearance	white-gray metallic
Pronunciation	/bəˈrɪliəm/ bə-RIL-ee-əm
Beryllium in the periodic table
– ↑ Be ↓ Mg lithium ← beryllium → boron
Atomic number (Z)	4
Group, block	group 2 (alkaline earth metals), s-block
Period	period 2
Element category	alkaline earth metal
Standard atomic weight (±) (Ar)	9.0121831(5)
Electron configuration	[He] 2s2
per shell	2, 2
Physical properties
Phase	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	+2, +1 ​(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
Miscellanea
Crystal structure	​hexagonal close-packed (hcp)
Speed of sound thin rod	12,890 m/s (at r.t.)
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
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 (1797)
First isolation	Friedrich Wöhler & Antoine Bussy (1828)
Most stable isotopes of beryllium
iso NA half-life DM DE (MeV) DP 7Be trace 53.12 d ε 0.862 7Li γ 0.477 – 9Be 100% 9Be is stable with 5 neutrons 10Be trace 1.36×106 y β− 0.556 10B

References

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