| Protactinium | |
| Elemental State | Pa |
| Electron Configuration | 1s22s22p63s23p63d104s24p64d104f145s25p65d106s26p67s26d15f2 |
| First Ionization Potential | 5.89 eV |
| Electron Affinity | |
| Z* | |
| Pauling Electronegativity | 1.5 |
| Covalent Radius | |
| Metallic Radius | 1.63 Å |
| Ionic Radius | |
| van der Waal's Radius | |
| Melting Point | 1572 oC |
| Boiling Point | |
| Density | 15.37 g/cm3 (calculated) |
| Other Properties | All isotopes are radioactive
231Pa half-life = 32500 years |