Compare chemical elements

	Selenium ✕
Symbol	Se
Atomic number	34
Chemical property	Reactive nonmetal
Origin o the name	the Greek selene, 'moon'
Group	16
Period	4
Atomic weight (u)	78.971
Atomic weight uncertainty (u)	0.008
Density (g/cm³)	4.809
Melting point (K)	453
Boiling point (K)	958
Heat capacity (J/(g·K))	0.321
Electro-negativity	2.55
Abundance in earth's crust (mg/kg)	0.05