Neptunium (Np) — Element 93: Properties & Data | Aladdin Scientific
Neptunium(Np) — Element 93
Neptunium (Np) is a actinide with atomic number 93 and atomic mass 237.048. It has melting point 917 K (644 °C), boiling point 4175 K (3902 °C), density 20.25 g/cm³. It sits in period 7 of the periodic table and was discovered in 1940.
Key facts
| Atomic mass | 237.0482 u |
|---|---|
| Electron configuration | [Rn]7s2 5f4 6d1 |
| Oxidation states | +6, +5, +4, +3 |
| Electronegativity (Pauling) | 1.36 |
| Atomic radius (van der Waals) | 221 pm |
| Ionization energy | 6.266 eV |
| Melting point | 917 K |
| Boiling point | 4175 K |
| Density | 20.25 g/cm³ |
| Standard state | Solid |
| Year discovered | 1940 |
Frequently asked questions
What is the electron configuration of neptunium?
The ground-state electron configuration of neptunium is [Rn]7s2 5f4 6d1.
What group and period is neptunium in?
Neptunium (Np) is in period 7 (actinide series) of the periodic table, classified as a actinide.
What is the melting point of neptunium?
Neptunium melts at 917 K (644 °C).
What is the standard state of neptunium?
Neptunium is a solid at standard temperature and pressure.
Related elements
About this data: property values compiled from IUPAC Standard Atomic Weights (2021), the NIST Atomic Spectra Database, and PubChem. Curated by the Aladdin Scientific technical team. Last reviewed: .