47Ag Silver

Year Discovered

Antiquity

Discovered By

Unknown

Biological Rating

Not necessary for life.

Description

The origins of its name are unknown. Silver is a soft, malleable metal. Its color is used to describe the colors of just about every other metal. Silver is stable in water and air, but sulfur compounds in air cause a black tarnish to appear. Silver will react with acids and bases. Humans have been using silver as far back as 3000 B.C.E. for jewelry, mirrors and silverware. Sterling silver is an alloy containing 92.5 % silver. The rest is usually copper, although other metals are used. It also is used as currency, with nations stockpiling tons and tons of the pure metal, although its usefulness for other purposes is reducing these stockpiles. Silver has the highest electrical conductivity of all the elements and is used in electric wires and connections, but cost limits its use for this purpose. Silver is also the best conductor of heat. Silver is also used in dental work, batteries and mirrors. Silver is the best reflector of visible light, so it makes the best mirrors, but silver mirrors tarnish quickly. The compounds silver bromide and silver nitrate are used in photography. About 30 % of all silver in the USA is used in photography. Silver iodide is used in cloud seeding to artificially cause rain. Silver is very poisonous to bacteria and other lower life forms, and someday may be used to purify drinking water. The symbol for silver, Ag, comes from its Latin name, argentum.

Biological Benefits

Silver has no known biological use.

Role in Life Processes

No known benefit for life processes.

Percentage Amount in the Human Body: 0.000003%

Sources

Silver is sometimes encountered in pure form. It also is mined from the minerals acanthite (silver sulfide) and stephanite. Silver also is found in the common minerals chlorargyrite (silver chloride) and polybasite. Silver is mined in many countries, but most comes from the USA, Canada, Mexico, Peru and Bolivia.