| name | Protactinium |
| latin | Protactinium |
| french | Protactinium |
| german | Protactinium |
| symbol | Pa |
| proton number | 91 |
| atomic weight | 231.03588 |
| Pauling electronegativity | 1.5 |
| electronic configuration | [Rn] 5f26d17s2 1s22s22p63s23p63d104s24p64d105s25p64f145d106s26p65f26d17s2 |
| melting point | 1841 K, 1568°C, 2854°F |
| boiling point | - |
| group | - |
| period | 7 |
| state (by 20°C) | solid |
| oxidation states | +4, +5 |
| Year of discovery | Discoverers |
| 1913 | Otto Hahn (1879-1968) Lise Meitner (1878-1968) Frederick Soddy (1877-1956) John Cranston |