| Attribute | Value |
|---|---|
| Symbol | He |
| Standard state | Gas |
| Atomic mass | 4.0026 u |
| Electron configuration | 1s² |
| Oxidation states |
|
| Atomic radius (van der waals) | 140 pm |
| Ionization energy | 24.587 eV |
| Melting point | 0.95 K |
| Boiling point | 4.22 K |
| Density | 0.0001785 g/cm³ |
| Atomic number | 2 |
| Group name | Noble gas |
| Discovered | 1868 year |
| Electronegativity (pauling scale) | Add |
| Electron affinity | Add |