Platinum (Pt) is a lustrous, silvery-white metallic element and a transition element. It was known to native South Americans before the arrival of Columbus, and was first taken to Europe in 1750; it is chiefly found in some ores of nickel. Malleable and ductile, platinum is used in jewelry, dentistry, electrical-resistance wire, magnets, thermocouples, surgical instruments, electrodes, and as a catalyst in catalytic converters in cars, for the contact process, and (alloyed with rhodium) for the Ostwald process.

 

Platinum is chemically unreactive and resists tarnishing and corrosion. These traits are shared with five other elements that, with platinum, and often found together as alloys and form the platinum group: iridium, osmium, palladium, rhodium, and ruthenium. Its most common isotope is ¹⁹⁵Pt (33.8%).

 

atomic number	78
relative atomic mass	195.09
relative density	21.45
melting point	1,772°C (3,222°F)
boiling point	3,800°C (6,872°F)