| 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 |
| 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 | |
 First
|
5.554 |
| Second
|
10.903 |
| Third
|
22.283 |
| Energy Levels |
|
| Kα1 (intensity 100) |
38.7247 KeV |
| Kα2 (intensity 50) |
38.1712 KeV |
| Kβ1 (intensity 22.1) |
43.826 KeV |
| Kβ2 (intensity 7.5) |
44.9165 KeV |
| Kβ3 (intensity 9.2) |
43.7033 KeV |
| Lα1 (intensity 100) |
5.4325 KeV |
| Lα2 (intensity 10) |
5.4078 KeV |
| Lβ1 (intensity 48) |
5.961 KeV |
| Lβ2 (intensity 18) |
6.339 KeV |
| Lβ3 (intensity 10) |
6.0695 KeV |
| Lβ4 (intensity 4) |
5.9555 KeV |
| Lγ1 (intensity 5.5) |
6.892 KeV |
| Lγ2 (intensity 2) |
7.1678 KeV |
| Lγ3 (intensity 2) |
5.363 KeV |
| Ll (intensity 4) |
4.8126 KeV |
| Atomic Radii |
|
| Empirical
|
185 pm |
| Bohr Radius
|
205 pm |
| Covalent Radius
|
No data. |
| Van der Waals
|
No data. |
| Triple covalent
|
No data. |
| Metallic
|
183.4 pm |
| Oxidation States |
|
| Main
|
Pm+3 |
| Other
|
|
Ionisation Energies (kJ mol-1)  |
|
| M - M+ |
535.9 |
| M+ - M2+ |
1052 |
| M2+ - M3+ |
2150 |
| M3+ - M4+ |
3970 |