Periodic Table
93
Np
237
Neptunium
ActinoidFirst transuranium element; multiple oxidation states.
Electronic Configuration
[Rn] 5f⁴ 6d¹ 7s²or1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 5f⁴ 6d¹ 7s²
Electron shells
2e⁻n=1
8e⁻n=2
18e⁻n=3
32e⁻n=4
22e⁻n=5
9e⁻n=6
2e⁻n=7
Properties
Atomic number
93
Atomic mass
237 u
Category
Actinoid
Block / Group / Period
f · — · 7
Valence electrons
2
Oxidation states
+3 to +7
Electronegativity
1.36
Atomic radius
175 pm
Ionization energy
605 kJ/mol
Electron affinity
46 kJ/mol
Melting point
917 K / 644 °C
Boiling point
4273 K / 4000 °C
Density
20.45 g/cm³
State at 25 °C
solid
Personal Notes
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