Np
Neptunium
Element 93 · Actinide · Period 7, Group 7
Solid · Discovered 1940
Atomic Properties
| Atomic Number | 93 |
| Atomic Mass | 237.048172u |
| Electron Configuration | [Rn]7s2 5f4 6d1 |
| Electronegativity | 1.36Pauling |
| Atomic Radius | 221pm |
| Ionization Energy | 6.266eV |
| Oxidation States | +6, +5, +4, +3 |
Physical Properties
| Standard State | Solid |
| Melting Point | 917K |
| Boiling Point | 4175K |
| Density | 20.25g/cm³ |
| Group Block | Actinide |
| Year Discovered | 1940 |