There is more to silver than the fact that it is a precious metal. For instance, did you know that it is the best known conductor of heat and electricity? In this ScienceStruck post, we will shed light on its properties and uses.
Silver is a chemical element having symbol Ag, atomic number 47, and standard atomic mass of 107.8682(2) u. Its chemical symbol, Ag is derived from the Latin word Argentum; 'arg' meaning shining or white. Though its claim to fame is its use in jewelry making, this soft, white transition metal has the highest electrical and thermal conductivity among metals.
Silver is either obtained in its pure native form, or as an alloy with gold and other metals. In fact, a large part of the total produce is the by-product of gold, copper, lead, and zinc refining. It is also found in minerals like argentite and chlorargyrite, albeit, in small quantities.
Chile, Mexico, Australia, China, Poland, and Peru are the major silver producing countries in the world. According to the British Geological Survey reports, in 2007, Chile was the leading producer, followed closely by Mexico.
A major chunk of the silver produced in the world comes from four mines, namely Uchucchacua in Proaño/Fresnillo in Mexico, Cannington in Australia, Dukat in Russia, and the Greens Creek Mine in Alaska.
★ Silver is a ductile, univalent coinage metal sporting a bright white metallic luster. Naturally occurring silver has 2 stable isotopes: 107Ag and 109Ag. Their atomic weight ranges between 92.950 u to 129.950 u.
★ Like we said, it has the highest conductivity among metals, even surpassing that of copper. If silver is not widely used like copper in electrical goods, it's only because of the fact that it is costly.
★ Silver halide, a compound of silver and one of the halogens, is remarkable for its ability to record a latent image that can be developed chemically.
★ Silver nitrate is formed by dissolving silver with nitric acid. Similarly, silver sulfide is formed when silver reacts with hydrogen sulfide.
★ Stable in pure air and water, it is tarnished when exposed to air or water containing ozone or hydrogen sulfide. However, dilute hydrochloric acid can be used to clean the black layer of silver sulfide.
★ Silver also has the highest thermal conductivity among metals. Additionally, it has high optical reflectivity and the lowest contact resistance of any metal.
★ Standard silver is an alloy of silver (92.5 percent) and copper (7.5 percent). It has a lower melting point compared to pure silver, and is also harder than the latter.
★ Silver is mostly used as a precious metal. Silver jewelry and silverware are made from sterling silver or standard silver. In the US, it should at least constitute 92.5 percent of fine silver in order to be marketable.
★ In a process known as 'flashing', a thin coat of .999 fine silver is applied on sterling silver jewelry to give it a shiny finish.
★ Britannia silver, which is an alloy of silver containing 95.84 percent silver and remaining part copper, is used to make tableware and wrought plates.
★ Amalgams used for dental fillings are made by debasing silver with mercury or tin.
★ 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 percent gold and 62.5 percent silver.
★ For its ability to record a latent image, silver halides are widely used in photography.
★ As their name suggests, high-capacity silver-cadmium batteries and silver-zinc batteries are also made from silver.
★ It is also used to make mirrors with superior reflectivity for visible light in a process known as silvering.
Silver has been known to mankind since 3000 BC, so it's difficult to find out who discovered it. Nevertheless, its uses, ranging from jewelry making to dentistry fillings, hint at the fact that it has been a prominent discovery for mankind.