| He | Helium | Noble Gas |
| Atomic number: | 2 | Atomic weight: | 4.002602 | ||
| Shells: | 2 | Orbitals: | 1s2 | ||
| Melting point: | -272.2°C @ 26 atmos. | Boiling point: | -268.934°C | ||
| Covalent radius: | 0.93 | Å | Atomic volume: | 19.5 | cm³/mol |
| Atomic radius: | 0.49 | Å | Ionic radius: | -- | Å |
| Electronegativity: | 0 | Oxidation states: | |||
| 1st ionization pot.: | 24.5874 | V | 2nd ionization pot.: | 54.416 | V |
| 3rd ionization pot.: | -- | V | Specific heat: | 5.193 | J/gK |
| Heat of fusion: | -- | kJ/mol | Heat of vapor.: | 0.0845 | kJ/mol |
| Thermal conduct.: | 0.00152 | W/cmK | Electrical conduct.: | -- | 10^6/cm ohm |
| Density: | 0.0001787 | g/cm³ | Valence: | 0 |