| Quantity | Value | Units | Value | Units |
| Atomic number | 1 | |||
| Atomic mass | 2.014101764(13) | g mole-1 | ||
| Density | 0.169 | g cm-3 | ||
| Mean excitation energy | 21.8 | eV | ||
| Minimum ionization | 2.019 | MeV g-1cm2 | 0.3411 | MeV cm-1 |
| Nuclear collision length | 51.3 | g cm-2 | 303.8 | cm |
| Nuclear interaction length | 71.8 | g cm-2 | 424.7 | cm |
| Pion collision length | 81.4 | g cm-2 | 481.8 | cm |
| Pion interaction length | 110.1 | g cm-2 | 651.6 | cm |
| Radiation length | 125.98 | g cm-2 | 745.4 | cm |
| Critical energy | 278.02 | MeV (for e-) | 271.50 | MeV (for e+) |
| Molière radius | 9.61 | g cm-2 | 56.86 | cm |
| Plasma energy |
8.35 | eV | ||
| Muon critical energy | 1592. | GeV | ||
| Boiling point @ 1 atm | 23.65 | K | -249.5 | C |
| Triple point | 18.69 | K | -254.5 | C |
| Index of refraction (@ STP, Na D) | 1.11 |