Neptunium: Properties


Atomic

  • Atomic Mass: 237.0482
  • Electronegativity:
    • Pauling: 1.36
    • Allred: 1.22
  • Polarizability: 24.8 3
  • Effective Nuclear Charge:
    • Slater: 1.8
  • Radius:
    • Np 3 +: 110 pm
    • Np 4 +: 95 pm
    • Np 5 +: 88 pm
    • Np 6 +: 82 pm
    • Atomic: 131 pm
  • Successive Ionization Energies:
    • Np - Np + : 597 kJ mol-1
  • Common Ions : Np 3 +, Np 4 +, Np 5 +, Np 6 +