Quick Facts
| Property | Value |
|---|---|
| Symbol | Np |
| Atomic Number | 93 |
| Atomic Mass | [237] u |
| Category | Actinide |
| Period | 7 |
| Group | 3 |
| Block | f |
| Electron Configuration | [Rn] 5f⁴ 6d¹ 7s² |
History and Discovery
Discovered by: Edwin McMillan and Philip Abelson Year of Discovery: 1940 Location: Berkeley, California, USA
Etymology
Named after Neptune, the planet beyond Uranus (just as neptunium is beyond uranium).
Applications and Uses
- Precursor for plutonium-238 production
- Neutron detection
- Nuclear waste component
Interesting Facts
- First transuranium element discovered
- Named following planetary naming convention
- Forms in nuclear reactors
- Longest-lived isotope (Np-237) has 2.14 million year half-life
- Found in trace amounts in uranium ores