Rhodium, a rare, white metallic element belonging to the platinum family. It occurs chiefly in platinum ores. Pure rhodium is tarnish-free and highly reflective, and is used as a coating on jewelry, silverware, and other objects.
Rhodium was discovered by the English scientist William Hyde Wollaston in 1803. Its name is derived from the rose-red color of some of its salts.
Symbol: Rh. Atomic number: 45. Atomic weight: 102.9055. Specific gravity: 12.4. Melting point: 3,571F. (1,966C). Boiling point: about 6,700 F. (3,700 C). Rhodium has one stable isotope, Rh-103. Rhodium belongs to Group VIII of the Periodic Table; its most common valence is +3.