| Quantity | Value | Units | Value | Units |
| <Z/A> | 0.47969 | |||
| Specific gravity (20° C, 1 atm) | 1.12 | g cm-3 | ||
| Mean excitation energy | 143.0 | eV | ||
| Minimum ionization | 1.645 | MeV g-1cm2 | 1.843 | MeV cm-1 |
| Nuclear collision length | 69.1 | g cm-2 | 61.73 | cm |
| Nuclear interaction length | 105.8 | g cm-2 | 94.46 | cm |
| Pion collision length | 95.3 | g cm-2 | 85.08 | cm |
| Pion interaction length | 135.9 | g cm-2 | 121.3 | cm |
| Radiation length | 23.65 | g cm-2 | 21.11 | cm |
| Critical energy | 43.24 | MeV (for e-) | 42.05 | MeV (for e+) |
| Molière radius | 11.60 | g cm-2 | 10.35 | cm |
Plasma energy ![]() |
21.12 | eV | ||
| Muon critical energy | 615. | GeV |
| Elem | Z | Atomic frac* | Mass frac* |
| 6 | |||
| 9 | |||
| 17 | |||
| * calculated from mass fraction data. | |||