Rhodium melted pellet. Image copyright: smart-elements.com
Rhodium is a moderately hard, silvery-white, metallic element belonging to the platinum group of transition elements. It was discovered by William Wollaston in London in 1803; its name comes from the Greek rhodon meaning "rose." It is the rarest metal on Earth and occurs associated with platinum. Its chief source is a by-product of nickel smelting.
Rhodium resists tarnishing and corrosion; it is used in hard platinum alloys, as a mirror surface, to plate jewelry, and in an alloy with platinum as a catalyst in the Ostwald process. Its most common isotope is 103Rh (100%).
|relative atomic mass||102.91|
|electron configuration||[Kr]4d8 5s1|
|melting point||1,966°C (3,571°F)|
|boiling point||3,727°C (6,741°F)|