| Element | Promethium | Symbol | Pm |
| Atomic Number | 61 | Molar Mass | 146.92 gmol-1 |
| Electron Configuration | [Xe]4f56s2 | Normal State | solid metal |
| Density @STP | 7.22 g cm-3 | Melting Point | 1042oC |
| Boiling Point | 3000oC | Stable Isotopes | |
| Atomic Radius | 181 pm | Ionic Radius | 106 (3+) pm |
| Electronegativity (Pauling) | Ionization Energy (1st) | 536 kJ mol-1 | |
| Ionization Energy (2nd) | 1052 kJ mol-1 | Ionization Energy (3rd) | 2150 kJ mol-1 |
| Molar Heat Capacity | 24.3 J K-1mol-1 | Standard Molar Entropy | J K-1mol-1 |
| Enthalpy of Fusion | 12.6 kJ mol-1 | Enthalpy of Vapourization | kJ mol-1 |