93 Np 237
Neptunium
actinide
Properties
- Atomic number
- 93
- Atomic mass
- 237 u
- Category
- actinide
- Group
- f-block
- Period
- 7
- Block
- f-block
- State (room temp)
- Solid
- Outer-shell electrons
- 2
- Electronegativity
- 1.36 (Pauling)
- Density
- 20.45 g/cm³
- Melting point
- 638.85 °C
- Boiling point
- 4173.85 °C
Electron configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f⁴ 6d¹
Noble-gas shorthand: [Rn] 5f⁴ 6d¹ 7s²
Electrons per shell: 2, 8, 18, 32, 22, 9, 2 — that's 2 in the outermost shell.
About Neptunium
Neptunium is a chemical element with symbol Np and atomic number 93. A radioactive actinide metal, neptunium is the first transuranic element. Its position in the periodic table just after uranium, named after the planet Uranus, led to it being named after Neptune, the next planet beyond Uranus.
- Discovered by Edwin McMillan
- Appearance: silvery metallic
Position in the periodic table
Data compiled from Wikipedia, PubChem, and IUPAC. Source.