| Quantity | Value | Units | Value | Units |
| Atomic number | 1 | |||
| Atomic mass | 1.00794(7) | g mole-1 | ||
| Density | 0.0600 | g cm-3 | ||
| Mean excitation energy | 21.8 | eV | ||
| Minimum ionization | 3.950 | MeV g-1cm2 | 0.2370 | MeV cm-1 |
| Nuclear collision length | 42.8 | g cm-2 | 714.0 | cm |
| Nuclear interaction length | 52.0 | g cm-2 | 866.8 | cm |
| Pion collision length | 70.4 | g cm-2 | 1173. | cm |
| Pion interaction length | 80.3 | g cm-2 | 1338. | cm |
| Radiation length | 63.04 | g cm-2 | 1051. | cm |
| Critical energy | 277.14 | MeV (for e-) | 270.62 | MeV (for e+) |
| Molière radius | 4.82 | g cm-2 | 80.40 | cm |
| Plasma energy |
7.03 | eV | ||
| Muon critical energy | 3095. | GeV |