All practice pages/Interatomic theory/Elements
Element 27, a transition metal
Named after a mine goblin, it makes the deepest blue in glass and porcelain and keeps the batteries of phones and electric cars running.
Period 4, group 9. The other transition metals are tinted, and every cell opens its own article.
Like other transition metals, cobalt loses its outer s electrons, and often some d electrons as well, to form positive ions, and it can form more than one kind.
Mined almost entirely as a byproduct of copper and nickel. The Democratic Republic of the Congo produces about three quarters of the world's supply. A single cobalt atom sits at the center of vitamin B₁₂.
Georg Brandt showed around 1735 that the blue color of certain ores came from a new metal, the first metal discovered since ancient times. Miners had long blamed these ores, which gave off poisonous arsenic fumes when smelted, on the kobold, a mischievous goblin of German folklore, and the name stuck.
Lithium-ion battery cathodes now use the largest share. Cobalt also goes into superalloys for jet engine turbine blades, strong magnets, hard cutting tools, and catalysts that remove sulfur from fuels. Cobalt blue has colored glass and porcelain for centuries, and radioactive cobalt-60 treats cancer and sterilizes medical supplies.