Name: zirconium
Symbol: Zr
Atomic number: 40
Atomic weight: 91.224 (2)
Group in periodic table: 4
Group name:
Period in periodic table: 5
Block in periodic table: d-block
CAS registry ID: 7440-67-7
Zirconium is a greyish-white lustrous metal. The finely divided metal can ignite spontaneously in air, especially at elevated temperatures. The solid metal is much more difficult to ignite. The inherent toxicity of zirconium compounds is low. Hafnium is invariably found in zirconium ores, and the separation is difficult. Commercial grade zirconium contains from 1 to 3% hafnium. The hafnium is removed from the zirconium used in the nuclear power industry.