Platinum is a chemical element with symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, gray-white transition metal.
Platinum is the least reactive metal. It has remarkable resistance to corrosion, even at high temperatures, and is therefore considered a noble metal. It is used in catalytic converters, laboratory equipment, electrical contacts and electrodes, platinum resistance thermometers, dentistry equipment, 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. Compounds containing platinum, most notably cisplatin, are applied in chemotherapy against certain types of cancer.