All practice pages/Interatomic theory/Elements
Element 45, a transition metal
One of the rarest and most expensive precious metals, working mostly out of sight inside car exhaust systems.
Period 5, group 9. The other transition metals are tinted, and every cell opens its own article.
Like other transition metals, rhodium loses its outer s electrons, and often some d electrons as well, to form positive ions, and it can form more than one kind.
Among the rarest elements in the crust, found with platinum in South Africa, which mines most of it, and in Russia.
William Hyde Wollaston found it in 1803 in platinum ore from South America, shortly after he found palladium. He named it from the Greek rhodon, rose, for the pink color of its salts.
About 80% goes into catalytic converters, where it breaks down the nitrogen oxides in car exhaust. Rhodium also plates white gold jewelry for a bright finish, coats mirrors and reflectors, makes thermocouples for very hot furnaces, and catalyzes the production of several industrial chemicals.