Selenium has an atomic number of 34, meaning each atom contains 34 protons in its nucleus.
The standard atomic weight of selenium is 78.971 u (unified atomic mass units).
Selenium is classified as a reactive nonmetal.
Selenium is a solid at 20 Β°C (68 Β°F).
The melting point of selenium is 220.85 Β°C / 494 K.
The boiling point of selenium is 684.85 Β°C / 958 K.
The density of selenium is 4.81 g/cmΒ³ (20Β°C).
Selenium has a Pauling electronegativity of 2.55.
The electron configuration of selenium is [Ar] 3d10 4s2 4p4.
Selenium commonly exhibits the following oxidation states: β2, +4, +6.
Selenium was discovered in 1817 by JΓΆns Jacob Berzelius.
Selenium is a stable element with no naturally occurring radioactive isotopes.
Essential trace nutrient.
Selenium is used for: Glass production; Solar cells; Pigments; Electronics.