| Quantity | Value | Units | Value | Units |
| Atomic number | 10 | |||
| Atomic mass | 20.1797(6) | g mole-1 | ||
| Specific gravity | 1.204 | g cm-3 | ||
| Mean excitation energy | 137.0 | eV | ||
| Minimum ionization | 1.695 | MeV g-1cm2 | 2.041 | MeV cm-1 |
| Nuclear collision length | 65.7 | g cm-2 | 54.58 | cm |
| Nuclear interaction length | 99.0 | g cm-2 | 82.22 | cm |
| Pion collision length | 91.8 | g cm-2 | 76.24 | cm |
| Pion interaction length | 128.7 | g cm-2 | 106.9 | cm |
| Radiation length | 28.93 | g cm-2 | 24.03 | cm |
| Critical energy | 55.10 | MeV (for e-) | 53.59 | MeV (for e+) |
| Molière radius | 11.13 | g cm-2 | 9.248 | cm |
| Plasma energy ℏωp | 22.26 | eV | ||
| Muon critical energy | 760. | GeV | ||
| Melting point | 24.56 | K | -248.6 | C |
| Boiling point @ 1 atm | 27.07 | K | -246.1 | C |
| Index of refraction (Na D) | 1.092 |