2

He

Helium

4.0026

Noble gas
Gas

Discovery

Ramsey, Sir William & Cleve, Per Teodor (1895)

Etymology

Greek

Meaning

Sun

Electron configuration

Electron configuration

Crystal structure

Crystal structure

Hexagonal close-packed

Physical Properties

Phase

  (at 21 °C and 101.325 kPa)

Gas

Melting point

  (at 101.325 kPa)

N/A

Boiling point

  (at 101.325 kPa)

-269.0 °C

4.15 K

Density

  (at 21 °C and 101.325 kPa)

0.18 g/cm3

Electronegativity

0.00