Atomic Properties
- Atomic Number
- 93
- Atomic Mass
- 237.0000 u
- Electron Configuration
- [Rn] 5f4 6d1 7s2
- Electronegativity
- 1.36
- Block
- f-block
- Group
- —
- Period
- 7
Physical Properties
- Phase (STP)
- solid
- Melting Point
- 912.00 K
- Boiling Point
- 4447.00 K
- Density
- 20.4500 g/cm³
About Neptunium
First transuranium element; named after planet Neptune.
Isotopes of Neptunium
Neptunium has 0 naturally occurring isotopes, plus 2 notable radioactive isotopes.
| Isotope | Mass Number | Atomic Mass (u) | Abundance | Type |
|---|---|---|---|---|
| 236Np | 236 | 236.04657 | — | Radioactive |
| 237Np | 237 | 237.0481736 | — | Radioactive |
Data source: NIH PubChem (aggregated from IUPAC, NIST)