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