Together with gold and the platinum-group metals, silver is one of the so-called precious metals. Because of its comparative scarcity, brilliant white colour, malleability, ductility, and resistance to atmospheric oxidation, silver has long been used in the manufacture of coins, ornaments, and jewelry. Silver has the highest known electrical and thermal conductivity of all metals and is used in fabricating printed electrical circuits and as a vapour-deposited coating for electronic conductors; it is also alloyed with such elements as nickel or palladium for use in electrical contacts. Silver also finds use as a catalyst for its unique ability to convert ethylene to ethylene oxide, which is a precursor of many organic compounds. Silver is one of the noblest—that is, least chemically reactive—of the transition elements.
