Helium
Electron Configuration: 2
Enthalpy of Fusion (kJ mol-1): 0.021
Enthalpy of Vaporisation (kJ mol-1): 0.082
Atomic Radii
Atomic Radius 31 pm
Bohr Radius 31 pm
Covalent Radius 32 pm
Van der Waals 140 pm
Ionisation Energies (kJ mol-1) show graph
M - M+ 2372.3
M+ - M2+ 5250.4