Symbol: Hf

Atomic number: 72

Atomic weight: 178.49

Boiling Point: 4450°C (8042.0F) to 4602.0 (8315.6F)

Melting Point: 2207°C(4004.6F) to 2503.0°C(4537.4F)

Density : 13.31 g/cm3 at 20.0°C (68.0 F)

Hafnium is a shiny, silvery, ductile metal that is corrosion-resistant and chemically

similar to zirconium. Its properties are influenced considerably by the impurities of

zirconium present. Of all the elements, zirconium and hafnium are two of the most

difficult to separate.

Because hafnium has a good absorption cross section for thermal neutrons (almost 600

times that of zirconium), has excellent mechanical properties, and is extremely

corrosion resistant, it is used for nuclear reactor control rods. And hafnium is also

used in filaments, electrodes, and the 45nm fabrication process for integrated

circuits.