SymbolZr
Latin nameZirkonium
Atomic number40
Period5
Element categoryTransition elements
Relative atomic mass91.244
GroupIV.B
Electronegativity
1.4
Oxidation numbers
4
Electron configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d2 5s2
Density [g/cm3]
6.506
State
Solid
Melting point [°C]
1852
Boiling point [°C]
3800
Atomic radius [pm]
206
Covalent radius [pm]
148
Thermal conductivity [W m-1K-1]
22.7
Heat capacity [J K-1g-1]
0.278
Discovery
1789
Hardness [Mohs scale]
5.0
Vickers hardness [MPa]
903
Brinell hardness [MPa]
650
Young's modulus [GPa]
68
Electrical conductivity [S m-1]
2.3 · 106
Shear modulus [GPa]
33
1.st ionization energy [eV]
6.6339
2.nd ionization energy [eV]
13.13
3.rd ionization energy [eV]
22.99
Stable isotopes
5
Unstable isotopes
16