Editing Period 5 element (section)

===Palladium===

{{main|Palladium}}

'''Palladium''' is a [[chemical element]] with the [[chemical symbol]] '''Pd''' and an [[atomic number]] of 46. It is a rare and lustrous silvery-white metal discovered in 1803 by [[William Hyde Wollaston]]. He named it after the [[2 Pallas|asteroid Pallas]], which was itself named after the [[epithet]] of the [[Greek mythology|Greek]] goddess [[Athena]], acquired by her when she slew [[Pallas (daughter of Triton)|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.

The unique properties of palladium and other platinum group metals account for their widespread use. A quarter of all goods manufactured today either contain PGMs or have a significant part in their manufacturing process played by PGMs.<ref>{{cite web|publisher=International Platinum Group Metals Association|title=Palladium|url=http://www.ipa-news.com/pgm/index.htm|url-status=dead|archive-url=https://web.archive.org/web/20100420034649/http://www.ipa-news.com/pgm/index.htm|archive-date=2010-04-20}}</ref> Over half of the supply of palladium and its [[Congener (chemistry)|congener]] platinum goes into [[catalytic converter]]s, which convert up to 90% of harmful gases from auto exhaust ([[hydrocarbons]], [[carbon monoxide]], and [[nitrogen dioxide]]) into less-harmful substances ([[nitrogen]], [[carbon dioxide]] and [[water vapor]]). Palladium is also used in electronics, [[dentistry]], [[medicine]], hydrogen purification, chemical applications, and groundwater treatment. Palladium plays a key role in the technology used for [[fuel cell]]s, which combine hydrogen and oxygen to produce electricity, heat, and water.

[[Ore]] [[Deposit (geology)|deposits]] of palladium and other PGMs are rare, and the most extensive deposits have been found in the norite belt of the [[Bushveld Igneous Complex]] covering the [[Transvaal Basin]] in South Africa, the [[Stillwater igneous complex|Stillwater Complex]] in [[Montana]], United States, the [[Thunder Bay District]] of [[Ontario]], Canada, and the [[Norilsk|Norilsk Complex]] in Russia. [[Recycling]] is also a source of palladium, mostly from scrapped catalytic converters. The numerous applications and limited supply sources of palladium result in the metal attracting considerable [[Palladium as an investment|investment]] interest.