Element overview
Helium (He) is element 2 with a listed atomic mass of 4.002602 u. It is in group 18 and period 1. Its category is noble gas.
Atomic properties
Electron configuration: 1s2. Electronegativity: not established. Common oxidation states: 0.
Physical properties
Density: 0.0001785; melting point: 0.95; boiling point: 4.22. Values depend on conditions, phase and source.