Hafnium

Symbol | Hf
Latin name | Hafnium
Atomic number | 72
Period | 6
Element category | Transition elements
Relative atomic mass | 178.49
Group | IV.B
Electronegativity | 1.3
Oxidation numbers | 4
Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d2 6s2
Density [g/cm3] | 13.3
State | Solid
Melting point [°C] | 2227
Boiling point [°C] | 4600
Atomic radius [pm] | 208
Covalent radius [pm] | 150
Thermal conductivity [W m-1K-1] | 23
Heat capacity [J K-1g-1] | 0.14
Discovery | 1864
Hardness [Mohs scale] | 5.5
Vickers hardness [MPa] | 1760
Brinell hardness [MPa] | 1700
Young's modulus [GPa] | 78
Electrical conductivity [S m-1] | 3.3 · 106
Shear modulus [GPa] | 30
1.st ionization energy [eV] | 6.8251
2.nd ionization energy [eV] | 14.925
3.rd ionization energy [eV] | 23.32
Stable isotopes | 6
Unstable isotopes | 15