Hafnium
element with the atomic number of 72 / From Wikipedia, the free encyclopedia
Hafnium is a chemical element. It has the chemical symbol Hf. It has the atomic number 72. It is a metal. It is silver gray. In chemistry it is placed in a group of metal elements named the transition metals. The chemistry of hafnium is similar to zirconium.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/3/38/Hf-crystal_bar.jpg/640px-Hf-crystal_bar.jpg)
Hafnium is found in zirconium minerals.
Hafnium is used in tungsten alloys in filaments and electrodes. It is also used as a neutron absorber in control rods in nuclear power plants.