Silver: The Element

Silver is a chemical element bearing the chemical symbol Ag, atomic number 47 and standard atomic mass of 107.8682(2) u. Its chemical symbol, Ag, is derived from the Latin word for silver Argentum, 'arg' meaning shining or white. This soft, white transition metal has the highest electrical and thermal conductivity among metals.

Silver is obtained in its pure native form, or as an alloy with gold and other metals. It is also found in minerals like argentite and chlorargyrite, in small amounts. A large part of silver is produced as the by-product of gold, copper, lead and zinc refining. Peru, Mexico, Australia, China, Poland and Chile are the major silver producing countries in the world. According to the British Geological Survey reports, in 2007, Chile was the leading silver producing nation, followed closely by Mexico. Uchucchacua in Proaño/Fresnillo in Mexico, Cannington in Australia, Dukat in Russia, and Greens Creek mine in Alaska account for the major part of world silver production.

Characteristics of Silver

Silver is a ductile univalent coinage metal sporting a bright white metallic luster. It has the highest conductivity among metals. Although its conductivity is even better than copper, being a costly metal restricts its use for electrical purposes. It also has the highest thermal conductivity among metals. This white metal has high optical reflectivity and the lowest contact resistance of any metal. Silver halide, a compound formed between silver and one of the halogens, is remarkable for its ability to record a latent image, that can be developed chemically later. Though stable in pure air and water, silver is tarnished when exposed to air or water containing ozone or hydrogen sulphide. Dilute hydrochloric acid can be used to clean the black layer of silver sulfide formed due to tarnishing.

Naturally occurring silver has 2 stable isotopes, ¹⁰⁷Ag and ¹⁰⁹Ag. Their atomic weight ranges from 93.943 u to 123.929 u. It is formed by dissolving silver with nitric acid. Silver sulphide is formed when silver reacts with hydrogen sulphide. Standard silver has a lower melting point compared to pure silver. It is also harder than pure silver.

Uses of Silver

Silver is mostly used as a precious metal. Silver jewelry and silverware are made from sterling silver or standard silver. Standard silver is an alloy of silver (92.5%) and copper (7.5%). In the US silver should at least constitute 92.5% of fine silver, in order to be marketable. In a process called 'flashing', a thin coat of .999 fine silver is applied on sterling silver jewelry to give it a shiny finish. Britannia silver, an alloy of silver containing 95.84% silver and remaining part copper, is used to make silver tableware and wrought plates.

A small amount of silver is added to carat gold solders and colored carat gold to give these alloys a pale color and improve its hardness. White 9-carat gold is made up of 37.5% gold and 62.5% silver. Amalgams used for dental fillings are made by debasing silver with mercury or tin. Silver is also used in photography in the form of silver halides. As their name suggests, high-capacity silver-cadmium batteries and silver-zinc batteries are made using silver. It is also used to make mirrors with superior reflectivity for visible light, in a process known as 'silvering'.

This transition metal has been known to mankind since 3000 BC. Today its uses range from making jewelry to dentistry fillings. This metal has truly been a prominent discovery for mankind, which is difficult to replace.