Quick answerNeptunium (Np) is an actinide with atomic number 93 and a mass number of 237 (the most stable isotope), in period 7. It was discovered by Edwin McMillan and Philip Abelson in 1940. It is used for neutron detection and nuclear waste research. Its electron configuration is [Rn] 5f4 6d1 7s2.
Neptunium was the first transuranium element ever made, and today it helps detect neutrons and study nuclear waste.
Key facts
| Symbol | Np |
|---|---|
| Atomic number | 93 |
| Atomic mass | [237] — mass number of the most stable isotope |
| Category | actinide |
| Group | — (f-block element, no group number) |
| Period | 7 |
| Block | f-block |
| Electron configuration | [Rn] 5f4 6d1 7s2 |
| Discovered | Edwin McMillan and Philip Abelson, 1940 |
| Uses | neutron detection, nuclear waste research, research |
Quick quiz
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Keep exploring
- Periodic table — all 118 elements
- Actinium (Ac) — another actinide, atomic number 89
- Thorium (Th) — another actinide, atomic number 90
- Protactinium (Pa) — another actinide, atomic number 91
- Uranium (U) — another actinide, atomic number 92
- Plutonium (Pu) — another actinide, atomic number 94
- Americium (Am) — another actinide, atomic number 95
- Curium (Cm) — another actinide, atomic number 96
- Berkelium (Bk) — another actinide, atomic number 97
- Californium (Cf) — another actinide, atomic number 98
- Einsteinium (Es) — another actinide, atomic number 99
- All actinide elements — on the periodic table
Sources & last updated
- CIAAW — Standard Atomic Weights
- PubChem Periodic Table
- Wikipedia — Timeline of chemical element discoveries
Last updated: . Figures are shown with their year; where sources disagree, the value is left out rather than estimated.