Helium

Noble gas

Symbol: He

Atomic Number: 2

Standard State: Gas

Atomic Mass: 4.0026

Electron Configuration: 1s2

Electronegativity:

Atomic Radius: 140

Ionization Energy: 24.587

Melting Point: 0.95

Boiling Point: 4.22

Density: 0.000179

Year Discovered: 1868