Symbol Hf Atomic radius: pm 156 Fusion: kJ/Mole 27.2
Name Hafnium Ionic radius: pm (+4)83 Boiling point: C 4603
Atomic number 72 Electron affinity ~0 Melting point: C 2233
Atomic weight 178.5 1st  ion potential 6.83 Specific Heat Cap: J/(g K) 0.14
Classification Trans metal Natural form Solid Thermal Cond: W/(cm K) 0.23
Configuration [Xe]4f145d26s2 Crystal structure Hex Electrical Cond 0.0312
Oxidation states 4 Density 13.3 Abundance: mg/kg-crust 3
Electronegativity 1.3 Vaporization: kJ/Mole 661.1    
Hafnium was discovered in 1923 by Dirk Coster and George Charles de Hevesy. Uses - nuclear control rods, gas-filled and incandescent lamps