Element overview
Selenium (Se) is element 34 with a listed atomic mass of 78.971 u. It is in group 16 and period 4. Its category is nonmetal.
Atomic properties
Electron configuration: not listed. Electronegativity: not established. Common oxidation states: not listed.
Physical properties
Density: not listed; melting point: not listed; boiling point: not listed. Values depend on conditions, phase and source.