platinum

Platinumis a chemical elementwith the chemical symbolPtand an atomic numberof 78. It is a dense, malleable, ductile, highly unreactive, precious, gray-white transition metal. Its name is derived from the Spanish termplatina, which is literally translated into "little silver". [ 1 ] [ 2 ] Platinum is a member of the platinum groupof elements and group 10of the periodic table of elements. It has six naturally occurring isotopes. It is one of the rarest elements in the Earth's crustwith an average abundance of approximately 5 μg/kg. It occurs in some nickeland copperores along with some nativedeposits, mostly in South Africa, which accounts for 80% of the world production. Because of its scarcity in the earth's crust, only a few hundred tonnesare produced annually, and is therefore highly valuable and is a major precious metal commodity. Platinum is the least reactive metal. It has remarkable resistance to corrosion, even at high temperatures, and is therefore considered a noble metal. Consequently, platinum is often found chemically uncombined as native platinum. Because it occurs naturally in the alluvial sandsof various rivers, it was first used by pre-ColumbianSouth American natives to produce artifacts. It was referenced in European writings as early as 16th century, but it was not until Antonio de Ulloapublished a report on a new metal of Colombianorigin in 1748 that it became investigated by scientists. Platinum is used in catalytic converters, laboratory equipment, electricalcontacts and electrodes, platinum resistance thermometers, dentistryequipment, and jewellery. Being a heavy metal, it leads to health issues upon exposure to its salts, but due to its corrosion resistance, it is not as toxic as some metals. [ 3 ]Compounds containing platinum, most notably cisplatin, are applied in chemotherapyagainst certain types of cancer. [ 4 ] Characteristics Physical Pure platinum is a lustrous, ductile, and malleable, silver-white metal. [ 5 ]Platinum is more ductilethan gold, silver or copper, thus being the most ductile of pure metals, but it is less malleable than gold. [ 6 ] [ 7 ]Pure platinum is slightly harder than pure iron.[ citation needed]The metal has excellent resistance to corrosion, is stable at high temperatures and has stable electrical properties. It does not oxidize at any temperature, although it is corroded by halogens, cyanides, sulfur, and caustic alkalis. Platinum is insoluble in hydrochloricand nitric acid, but dissolves in hot aqua regiato form chloroplatinic acid, H2PtCl6.Blog Directory at OnToplist.comBlog Directory | Submit to Directories and Promote your BlogsBlog Directory at OnToplist.com