93
237 u
Np
Neptunium
Actinide
Atomic Structure
Physical State
Group
N/A
Period
7
Block
f
Electron Configuration
[Rn] 5f⁴ 6d¹ 7s²
Physical Properties
Atomic Mass:
237 u
Electronegativity:
1.36
Atomic Radius:
190 pm
Ionization Energy:
6.266 eV
Density:
20.45 g/cm³
Melting Point:
917 K
Boiling Point:
4273 K
Historical Information
Discovered By:
Edwin McMillan
Year Discovered:
1940