Hydrogen Hydrogen Bond Hydrogen Chloride Hydrogen Cyanide Hydrogen Peroxide Hydrogenation Hydrogen-Oxygen Fuel Cell Hydrolysis Hydrolysis Constant Hydrometer Hydrophilic Colloids Hypothesis Hafnium , symbol Hf, metallic element that closely resembles zirconium . Hafnium was discovered in Copenhagen in 1923 by the Hungarian chemist Georg von Hevesy and the Dutch physicist Dirk Coster. On the basis of a prediction by the Danish physicist Niels Bohr that element 72 would resemble zirconium in structure, they looked for the element in zirconium ores. Hafnium is found in nearly all ores of zirconium and is 45th in order of abundance of the elements in the crust of the earth. It resembles zirconium so closely in chemical properties and crystal structure that separation of the two elements is extremely difficult.
Separation is accomplished most efficiently by means of the ion -exchange technique.
Hafnium is used in the manufacture of tungsten filaments. Because of its resistance to high temperature s, it is used with zirconium as a structural material in nuclear power plants. The atomic weight of hafnium is 178.49. All Rights Reserved Worldwide.