34Se
Selenium
셀레늄 · セレン
Nonmetal
Atomic number34
ElementSe — Selenium
Atomic mass78.971
CategoryNonmetal
Group16
Period4
Electron config[Ar] 3d10 4s2 4p4
Shells2,8,18,6
State (RT)Solid
Melting pt221°C
Boiling pt685°C
Electronegativity2.55
Discovered1817
Main usesPhotocells, glass tinting
2 · 8 · 18 · 6