34

Se

Selenium

78.971

Nonmetal
Solid

Discovery

Berzelius, Jöns Jacob (1817)

Etymology

Greek

Meaning

Moon

Electron configuration

Electron configuration

Crystal structure

Crystal structure

Hexagonal

Physical Properties

Phase

  (at 21 °C and 101.325 kPa)

Solid

Melting point

  (at 101.325 kPa)

217.0 °C

490.15 K

Boiling point

  (at 101.325 kPa)

613.0 °C

886.15 K

Density

  (at 21 °C and 101.325 kPa)

4.79 g/cm3

Electronegativity

2.55