Silver

Pure silver has the highest electrical and thermal conductivity of all metals and the lowest contact resistance.   It also is very ductile and malleable.   The most important industrial use of silver is in photography, where about 30% of it is used as silver nitrate (lunar caustic).   It is used for dental work, solder and brazing alloys, electrical contacts, and high capacity silver-zinc and silver-cadmium batteries.   Silver paints are used in printed circuit boards.   Silver mirrors are made by chemical deposition, electrodeposition, or by evaporation onto glass or metals.   Silver iodide is used to seed clouds to produce rain.   Silver chloride can be made transparent and used to cement glass.   Silver is no longer used in coinage. ^{Lide 4-27}

Silver is non-toxic, but most of its salts are toxic.   They are absorbed in the circulatory system and deposited as reduced compounds.   This malady manifested itself as a greyish skin and mucuous membranes, a condition called argyria. ^{Lide 4-27}

Silver has been known since ancient times.   Silver is found free and in ores, such as argentite, Ag₂S, and horn silver, AgCl, and in lead, lead-zinc, copper, gold, and copper-nickel ores.   It is also obtained from the electrolytic refining of copper. ^{Lide 4-27}