Palladium Palladium Palladium is a chemical element with symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired by her when she slew Pallas. Palladium, platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs). These have similar chemical properties, but palladium has the lowest melting point and is the least dense of them. More than half the supply of palladium
Rare-earth element the 17 rare-earth elements, their atomic number and symbol, the etymology of their names, and their main usages (see also Applications of lanthanides) is provided here. Some of the rare-earth elements are named after the scientists who discovered or elucidated their elemental properties, and some after their geographical discovery. The following abbreviations are often used: The first rare-earth element discovered was the black mineral "ytterbite" (renamed to gadolinite in 1800). It was discovered by Lieutenant Carl Axel Arrhenius in 1787 at a quarry in the village of Ytterby, Sweden. Arrhenius's "ytterbite" reached Johan Gadolin, a Royal Academy of Turku professor,