Group 12 element people in the 17th century. German chemist Andreas Marggraf is usually given credit for discovering pure metallic zinc in a 1746 experiment by heating a mixture of calamine and charcoal in a closed vessel without copper to obtain a metal. Experiments on frogs by the Italian doctor Luigi Galvani in 1780 with brass paved the way for the discovery of electrical batteries, galvanization and cathodic protection. In 1880, Galvani's friend, Alessandro Volta, invented the Voltaic pile. The biological importance of zinc was not discovered until 1940 when carbonic anhydrase, an enzyme that scrubs carbon dioxide from blood, was shown to
Group 3 element 10,000 USD/kg, or about one-fourth that of gold. Lanthanum is much more common, being the second most abundant rare earth, and in addition to monazite can also be extracted economically from bastnäsite. The most available element in group 3 is yttrium, with annual production of 8,900 tonnes in 2010. Yttrium is mostly produced as oxide, by a single country, China (99%). Lutetium and scandium are also mostly obtained as oxides, and their annual production by 2001 was about 10 and 2 tonnes, respectively. Group 3 elements are mined only as a byproduct from the extraction of other elements. The metallic