palladium (chemistry)

Lightweight, ductile and malleable, silver-white, metallic element, atomic number 46, relative atomic mass 106.4. Together with the elements ruthenium, rhodium, osmium, iridium, and platinum, it forms the group of platinum metals, which have similar physical and chemical properties. Like the other platinum metals it is resistant to tarnish and corrosion. It often occurs in nature as a free metal (see native metal) in a natural alloy with platinum. Palladium is used as a catalyst, in alloys of gold (to make white gold) and silver, in electroplating, and in dentistry.

It was discovered in 1803 by English physicist William Wollaston, and named after the asteroid Pallas (found in 1802).