Atomic number 93
Neptunium
Actinide
Quick facts
- Atomic mass
- 237.00
- Group
- —
- Period
- 7
- State (STP)
- solid
- Electronegativity
- 1.36
- Common ox. states
- +3, +4, +5, +6, +7
Properties
Electron configuration
[Rn] 5f⁴ 6d¹ 7s²
- Ionization energy
- 604.5 kJ/mol
- Electron affinity
- —
- Melting point
- 917.00 K (643.9 °C)
- Boiling point
- 4273.00 K (3999.8 °C)
How it bonds· family overview
Neptunium (Np) is an actinide. Like the lanthanides it tends toward a +3 oxidation state, but the early actinides (Th–Am) routinely access +4, +5, +6, even +7 because the 5f electrons are easier to ionize. Most actinides are radioactive; their "bonding" in school is read off the periodic table, not measured in lab.