Se - Selenium

Selenium

 Selenium 
Se
Atomic Number: 34
Atomic Weight: 78.96
Element Type: Non-Metal
Crystal Structure: Hexagonal
Melting Point: 221.0°C = 429.8°F = 494.15 K
Boiling Point: 685.0°C = 1265.0°F = 958.15 K
Critical Temp: 1493.0°C = 2719.4°F = 1766.15 K
Atomic Radius: 1.22 Å (Å = Angstrom = 10-10 m)
Covalent Radius: 1.16 Å
Electronegativity: 2.55

History

(Gr. Selene, moon) Discovered by Berzelius in 1817, who found it associated withtellurium, named for the earth.


Sources