silver, Metallic chemical element, one of the transition elements, chemical symbol Ag, atomic number 47. It is a white, lustrous precious metal, valued for its beauty. It is also valued for its electrical conductivity, which is the highest of any metal. Between copper and gold in their common group of the periodic table, it is intermediate between them in many properties. Widely distributed in nature in small amounts, as the native metal and in ores, it is usually recovered as a by-product of copper and lead production. Its use in bullion and coins was overtaken in the 1960s by demand for industrial purposes, especially photography. It is also used in printed electrical circuits, electronic conductors, and contacts. It is the catalyst for converting ethylene to ethylene oxide, the precursor of many organic chemicals. Its use in alloys in sterling (92.5% silver, 7.5% copper) and plated silverware, ornaments, and jewelry remains important; yellow gold used in jewelry is typically 25% silver, and gold dental alloys are about 10% silver. Silver dental fillings are an amalgam of silver and mercury. Silver in compounds, the most important of which is silver nitrate, has valence 1. Its chloride, bromide, and iodide are used in photography and its iodide in cloud seeding.
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