Element | Protactinium | Symbol | Pa |
Atomic Number | 91 | Molar Mass | 231.04 g mol-1 |
Electron Configuration | [Rn]5f26d17s2 | Normal State | solid metal |
Density @STP | 15.37 g cm-3 | Melting Point | 1572oC |
Boiling Point | 4000oC | Stable Isotopes | none |
Atomic Radius | 161 pm | Ionic Radius | 89 (5+) pm |
Electronegativity (Pauling) | 1.5 | Ionization Energy (1st) | 568 kJ mol-1 |
Ionization Energy (2nd) | 1129 kJ mol-1 | Ionization Energy (3rd) | 1814 kJ mol-1 |
Molar Heat Capacity | 22.9 J K-1mol-1 | Standard Molar Entropy | 198.1 J K-1mol-1 |
Enthalpy of Fusion | 16.7 kJ mol-1 | Enthalpy of Vapourization | 481 kJ mol-1 |