93
Np
neptunium
[237]

General properties

Group
n/a
Period
period 7
Category
actinoids
Standard atomic weight
-
Melting point
912±3 K (639±3 °C)
Boiling point
4447 K (4174 °C)
Phase at STP
solid

Additional properties

Block
f-block
Electron configuration
[Rn] 5f⁴ 6d¹ 7s²
Electrons per shell
2, 8, 18, 32, 22, 9, 2
Electronegativity
1.36
Density
alpha: 20.45 g/cm³ accepted standard value: 19.38 g/cm³
Oxidation states
+2, +3, +4, +5, +6, +7 (an amphoteric oxide)
CAS Number
7439-99-8