Silver

Atomic Number: 47

Symbol: Ag

Atomic Weight: 107.8682

Discovery: Known since prehistoric time. Man learned to separate silver from lead as early as 3000 B.C.

Electron Configuration: [Kr]5s14d10

Word Origin: Anglo-Saxon Seolfor or siolfur; meaning 'silver', and Latin argentum meaning 'silver'

Properties: The melting point of silver is 961.93C, boiling point is 2212C, specific gravity is 10.50 (20C), with a valence of 1 or 2. Pure silver has a brilliant white metallic luster. Silver is slightly harder than gold. It is very ductile and malleable, exceeded in these properties by gold and palladium. Pure silver has the highest electrical and thermal conductivity of all metals. Silver possesses the lowest contact resistance of all metals. Silver is stable in pure air and water, although it tarnishes upon exposure to ozone, hydrogen sulfide, or air containing sulfur.

Uses: The alloys of silver have many commercial uses. Sterling silver (92.5% silver, with copper or other metals) is used for silverware and jewelry. Silver is used in photography, dental compounds, solder, brazing, electrical contacts, batteries, mirrors, and printed circuits. Freshly deposited silver is is the best known reflector of visible light, but it rapidly tarnishes and loses its reflectance. Silver fulminate (Ag2C2N2O2) is a powerful explosive. Silver iodide is used in cloud seeding to produce rain. Silver chloride can be made transparent and is also used as a cement for glass. Silver nitrate, or lunar caustic, is used extensively in photography. Although silver itself is not considered toxic, most of its salts are poisonous, due to the anions involved. Exposure to silver (metal and soluble compounds) should not exceed 0.01 mg/M3 (8 hour time-weighted average for a 40 hour week). Silver compounds can be absorbed into the circulatory system, with deposition of reduced silver in body tissues. This may result in argyria, which is characterized by a greyish pigmentation of the skin and mucous membranes. Silver is germicidal and may be used to kill many lower organisms without harm to higher organisms. Silver is used as coinage in many countries.

Sources: Silver occurs native and in ores incuding argentite (Ag2S) and horn silver (AgCl). Lead, lead-zinc, copper, copper-nickel, and gold ores are other prinicipal sources of silver. Commercial fine silver is at least 99.9% pure. Commercial purities of 99.999+% are available.

Element Classification: Transition Metal

Density (g/cc): 10.5

Appearance: silvery, ductile, malleable metal

Atomic Radius (pm): 144

Atomic Volume (cc/mol): 10.3

Covalent Radius (pm): 134

Ionic Radius: 89 (+2e) 126 (+1e)

Specific Heat (@20C J/g mol): 0.237

Fusion Heat (kJ/mol): 11.95

Evaporation Heat (kJ/mol): 254.1

Debye Temperature (K): 215.00

Pauling Negativity Number: 1.93

First Ionizing Energy (kJ/mol): 730.5

Oxidation States: 2, 1

Lattice Structure: Face-Centered Cubic

Lattice Constant (): 4.090

Silver possesses, it's working qualities similar to gold but can achieve the most brilliant polish of any metal. To make it durable for jewelry, however, pure silver (999 fineness) is often alloyed with small quantities of copper. In many countries, Sterling Silver (92.5% silver, 7.5% copper) is the standard for Jewelry and has been since the 14th century.

The copper toughens the silver and makes it possible to use silver 925 for decorative and fashionable jewelry.

Throughout the ages, silver jewelry has been associated with magical powers; believed to promote healing, bring good luck and for warding off evil spirits to the wearer.

While these beliefs are not part of mainstream thinking today, some people still hold them true.

Silver has always been held in high esteem and displayed as a status symbol since it was mined approx. 4,000 BC in Asia Minor.

In the earliest Egyptian records, it was considered more precious than gold. Interestingly, with all of silver's magical power, owning silver at various times was restricted, especially if it was in the form of jewelry. Throughout history, wearing silver jewelry was often a social privilege - not a right - reserved only for upper classes.

By the 18th century, things began to change in Europe and a new fashion fad surfaced: silver buckles appeared on shoes where laces had always been. Although today we generally consider shoe buckles to be functional items, back in the 1700's, they were a form of jewelry.

Silver jewelry was a significant indicator of status until the very end of the 18th century, because it was limited to a privileged few. It was the Industrial Revolution, through mass manufacturing, which finally made jewelry available to the general population.

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