40
Zr
zirconium
91.224

General properties

Group
group 4
Period
period 5
Category
transition metals
Standard atomic weight
91.224(2)
Melting point
2128 K (1855 °C)
Boiling point
4650 K (4377 °C)
Phase at STP
solid

Additional properties

Block
d-block
Electron configuration
[Kr] 4d² 5s²
Electrons per shell
2, 8, 18, 10, 2
Electronegativity
1.33
Density
6.52 g/cm³
Oxidation states
−2, +1, +2, +3, +4 (an amphoteric oxide)
CAS Number
7440-67-7