Protactinium
Actinide| Atomic number | 91 |
|---|---|
| Category | Actinide |
| Atomic mass | 231.04 |
| Electron configuration | [Rn]5f² 6d¹ 7s² |
| Oxidation states | +4, +5 |
| Electronegativity | 1.5 |
| Melting point | 1,572 °C |
| Boiling point | 4,000 °C |
| Density | 15.37 g/cm³ |
| Crystal structure | Tetragonal |
| Period | 7 |
| Block | f |
| Discovered | 1,913 |
| Crustal abundance | 0 ppm |