Element overview
Beryllium (Be) is element 4 with a listed atomic mass of 9.0121831 u. It is in group 2 and period 2. Its category is alkaline earth metal.
Atomic properties
Electron configuration: [He] 2s2. Electronegativity: 1.57. Common oxidation states: +2.
Physical properties
Density: 1.85; melting point: 1560; boiling point: 2742. Values depend on conditions, phase and source.