Neptunium |
| Symbol | Np |
|---|---|
| Latin name | Neptunium |
| Atomic number | 93 |
| Period | 7 |
| Element category | Inner transition elements |
| Relative atomic mass | 237.0482 |
| Group | III.B |
| Electronegativity | 1.3 |
| Oxidation numbers | 3, 4, 5, 6, 7 |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p6 5f4 6d1 7s2 |
| Density [g/cm3] | 20.25 |
| State | Solid |
| Melting point [°C] | 640 |
| Boiling point [°C] | 3900 |
| Thermal conductivity [W m-1K-1] | 6.3 |
| Discovery | 1940 |
| Electrical conductivity [S m-1] | 8.3 · 105 |
| 1.st ionization energy [eV] | 6.2657 |
| Stable isotopes | 0 |
| Unstable isotopes | 15 |