| Promethium | |
| Electrons per shell | 2,8,18,23,8,2 |
| Electron Configuration | [Xe] 4f5 6s2 ![]() |
| Ground state | 6H°5/2 |
| Atomic Volume | 22.39 cm3 mol-1 |
| Electronegativity | 1.13 |
| Magnetic ordering | No data |
Thermal Properties |
|
| Enthalpy of Atomization | 310 kJ mol-1 @25°C |
| Enthalpy of Fusion | 12.6 kJ mol-1 |
| Enthalpy of Vaporisation | No data. |
| Heat Capacity | No data. |
| Thermal Conductivity | 17.9 W m-1 K-1 |
| Thermal Expansion | est. 11 μm m-1 K-1 |
| Critcal Temperature | No data. |
| Critcal Pressure | No data. |
| Adiabatic index | No data. |
Elastic Properties |
|
| Bulk modulus | est. 33 GPa |
| Poisson ratio | est. 0.28 |
| Shear modulus | est. 18 GPa |
| Young's modulus | est. 46 GPa |
Electrical Properties |
|
| Electrical resistivity | 7.5 x 10-7 Ω m |
| Electrical conductivity | ? 106/cm Ω |
Chemical Properties |
|
| Electrochemical Equivalent | 1.8022 g Ah-1 |
| Valence Electron Potential (-eV) | 44.1 |
| Ionization Potential | |
| 5.554 | |
| 10.903 | |
| 22.283 | |
Energy Levels |
|
| 38.7247 KeV | |
| 38.1712 KeV | |
| 43.826 KeV | |
| 44.9165 KeV | |
| 43.7033 KeV | |
| 5.4325 KeV | |
| 5.4078 KeV | |
| 5.961 KeV | |
| 6.339 KeV | |
| 6.0695 KeV | |
| 5.9555 KeV | |
| 6.892 KeV | |
| 7.1678 KeV | |
| 5.363 KeV | |
| 4.8126 KeV | |
Atomic Radii |
|
| 185 pm | |
| 205 pm | |
| No data. | |
| No data. | |
| No data. | |
| 183.4 pm | |
Ionic Radii (Å) |
||||
| Charge | Coordination | Crystal | Ionic | Key |
| 3 | VI | 1.11 | 0.97 | R |
| VIII | 1.233 | 1.093 | R | |
| IX | 1.284 | 1.144 | R | |
| R, From r3 vs V plots. |
| C, Calculated from bond length - bond strength equations. |
| E, Estimated. |
| *, Most Reliable. |
| M, From Metallic Oxides. |
| A, Ahrens (1952) Ionic radius. |
| P, Pauling's (1960) Crystal Radius. |
Oxidation States |
|
| Pm+3 | |
Ionisation Energies (kJ mol-1) ![]() |
|
| 535.9 | |
| 1052 | |
| 2150 | |
| 3970 | |