Periodic Table of Elements

4

Beryllium

9.0122

Beryllium was discovered by French chemist Louis-Nicolas Vauquelin (1763-1829) in 1798. The name beryllium was adopted officially in 1957.

Name: Beryllium
Symbol: Be
Atomic number: 4
Atomic weight: 9.0122
State: gas
Group, period, block: 2, 2, s
Color: white-gray metallic
Classification: alkaline earth metal
Electron configuration: 1s2 2s2
2,2

Physical properties

Density: 1.85 g/cm-3
Melting point: 1560 K, 1287 C, 2349 F
Boiling point: 2742 K, 2469 C, 4476 F

Atomic properties

Oxidation states: 2, 1
Electronegativity: 1.57 (Pauling scale)
Ionization energies: 1st: 899.5 kJ mol-1
Covalent radius: 963 pm
Van der Waals radius: 153 pm
  • Be
  • Electron Configuration

Isotopes

There is only one naturally occurring isotope of beryllium, 9Be.