| Quantity | Value | Units | Value | Units |
| Atomic number | 88 | |||
| Atomic mass | [226.02541(2)] | g mol-1 | ||
| Density | 5.000 | g cm-3 | ||
| Mean excitation energy | 826.0 | eV | ||
| Minimum ionization | 1.111 | MeV g-1cm2 | 5.555 | MeV cm-1 |
| Nuclear interaction length | 205.5 | g cm-2 | 41.09 | cm |
| Nuclear collision length | 116.9 | g cm-2 | 23.38 | cm |
| Pion interaction length | 231.5 | g cm-2 | 46.30 | cm |
| Pion collision length | 139.9 | g cm-2 | 27.99 | cm |
| Radiation length | 6.15 | g cm-2 | 1.230 | cm |
| Critical energy | 7.19 | MeV (for e-) | 6.94 | MeV (for e+) |
| Muon critical energy | 137. | GeV | ||
| Molière radius | 18.12 | g cm-2 | 3.625 | cm |
| Plasma energy ℏωp | 40.21 | eV |