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 |