93 Np
Actinide
Neptunium
First transuranium element.
Properties of Neptunium
- Atomic number (Z)
- 93
- Symbol
- Np
- Atomic mass
- 237 g/mol
- Category
- Actinide
- Group
- 3
- Period
- 7
- Electron configuration
- [Rn] 5f⁴ 6d¹ 7s²
- Electronegativity (Pauling)
- 1.36
- Atomic radius
- 175 pm
- First ionization energy
- 605 kJ/mol
- Melting point
- 917 K (643.9 °C)
- Boiling point
- 4273 K (3999.8 °C)
- Density
- 20.45 g/cm³
- Phase at 25 °C
- Solid
- Discovered
- Discovered in 1940
Frequently asked questions
What is Neptunium?
Neptunium (Np) is an actinide, element number 93 on the periodic table. First transuranium element.
What is the atomic number and atomic mass of Neptunium?
Neptunium has atomic number 93 and an atomic mass of about 237 g/mol.
What is the electron configuration of Neptunium?
The electron configuration of Neptunium is [Rn] 5f⁴ 6d¹ 7s².
Where is Neptunium on the periodic table?
Neptunium sits in group 3, period 7, and is classified as a actinide.