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 |