93 Np 237
Neptunium
Actinide
Neptunium (Np) is a chemical element with atomic number 93, classified as a actinide. At room temperature it is a solid. It was discovered in 1940 by Edwin McMillan, Philip Abelson.
Properties
- Atomic number
- 93
- Atomic mass
- 237 u
- Category
- Actinide
- Group
- 0
- Period
- 7
- Block
- f-block
- Electron configuration
- [Rn] 5f⁴ 6d¹ 7s²
- Phase at STP
- Solid
- Density
- 20.45 g/cm³
- Melting point
- 917 K (643.9 °C)
- Boiling point
- 4273 K (3999.8 °C)
- Electronegativity
- 1.36
- Atomic radius
- 221 pm
- Ionization energy
- 6.266 eV
- Discovery
- 1940 · Edwin McMillan, Philip Abelson
Common uses
Nuclear reactors, research, neutron detectors
Did you know?
First transuranium element discovered and named after Neptune.