|Atomic mass||107.868 amu|
Silver, taken from the Latin name, argentium, is of ancient origin. Its products and refining methods are described in the Bible and early Egyptian writings. Silver occurs as the metal and in silver ores such as argentite (Ag2S). Such sulphide ores often accompany copper, lead, and zinc ores. Silver is found in many parts of Canada. Important deposits are located near Cobalt, Ontario, Keremos, B.C. and at several locations in the Yukon and Northwest Territories.
Silver is a relatively soft metal which can be readily electrodeposited. It is extremely sensitive to contamination by sulfur as silver sulfide tarnishes silver. Silver is ductile and malleable. It is usually alloyed with at least one other metal. The alloying metals not only dilute the silver content to make it more economical, but enhance its physical properties as well. Sterling silver is about 93% sliver and 7% copper.
Current production of silver is mainly fromt eh recovery from the sludge that is produced during the electrolytic purification of copper.
Commercial applications of silver include its use:
- in electrical circuitry as it has the highest electrical conductivity of any metal.
- in "silver solder". Silver solder has a higher melting point (>600°C) than soft-solder. This forms a strong joint in copper pipes, one which is less likely to corrode and leak, and also stands much higher pressure.
- in medicine and dentistry as it has antiseptic properties.
- its use in batteries.
- in photography. This includes silver-containing compounds such as:
- silver nitrate, AgNO3, is one of the essential ingredients in photographic emulsions.
- silver bromide, AgBr. Photographic film consists of a dispersion of fine silver bromide crystals in an emulsion that is coated on a plastic sheet. Exposure to light "activates" those crystals upon which the light falls by converting a few silver ions to silver atoms.
- silver chloride, AgCl, is also used extensively in the manufacture of photographic emulsions.
- as the rain-making chemical. Yellowish crystals of silver iodide, AgI, can be sprinkled into moisture-bearing clouds to encourage precipitation. Silver iodide is harmless to animal and vegetable life.
- as explosives.