| Quantity | Value | Units | Value | Units |
| Atomic number | 20 | |||
| Atomic mass | 40.078(4) | g mole-1 | ||
| Specific gravity | 1.550 | g cm-3 | ||
| Mean excitation energy | 191.0 | eV | ||
| Minimum ionization | 1.655 | MeV g-1cm2 | 2.566 | MeV cm-1 |
| Nuclear collision length | 75.8 | g cm-2 | 48.89 | cm |
| Nuclear interaction length | 119.8 | g cm-2 | 77.31 | cm |
| Pion collision length | 101.4 | g cm-2 | 65.44 | cm |
| Pion interaction length | 148.8 | g cm-2 | 96.02 | cm |
| Radiation length | 16.14 | g cm-2 | 10.42 | cm |
| Critical energy | 29.56 | MeV (for e-) | 28.71 | MeV (for e+) |
| Molière radius | 11.58 | g cm-2 | 7.471 | cm |
| Plasma energy ℏωp | 25.34 | eV | ||
| Muon critical energy | 447. | GeV |