Atomic Number: 47
Atomic Symbol: Ag
Atomic Weight: 107.8682
Melting Point: 1,763.2 F (961.78 C)
Boiling Point: 3,923.6 F (2,162 C)
Word origin: The word silver is from the Anglo-Saxon word seolfor. (No other English word rhymes with silver.) Silver’s atomic symbol, Ag, comes from the Latin word for silver, argentums.
Discovery: People have known about silver since ancient times. It is mentioned in the Bible. Humans learned to separate silver from lead as early as 3000 B.C.
Properties of silver
Pure silver is a beautiful metal with a brilliant white luster. It is stable in pure air and water, but tarnishes when exposed to ozone, hydrogen sulfide or air containing sulfur. It is slightly harder than gold but still very ductile and malleable. The only more ductile metals are gold and perhaps palladium. Pure silver has the highest electrical and thermal conductivity of all metals and the lowest contact resistance. [See Periodic Table of the Elements]
Silver itself is not toxic, but most of its salts are. Silver can be a germicide, killing many lower organisms without harming higher animals. Silver compounds can be absorbed into the circulatory system, and reduced silver can be deposited into various bodily tissues. If this happens, a condition known as argyria can result. Argyria is characterized by grayish skin pigmentation and mucous membranes. Exposure to silver as a metal and soluble compound in air should not exceed 0.01 milligrams per cubic meterper 40-hour workweek.
Commercial fine silver is at least 99.9 percent pure. Silvers up to99.999+ percent pure are available commercially.
Sources of silver
Silver occurs organically in ores such as argentite and horn silver, lead, lead-zinc, copper, gold and copper-nickel. Silver can also be recovered through electrolytic copper refining.
Silver mineral deposits are found all over the world.
Uses of silver
One of the most famous metals, silver appears frequently in everyday life. For centuries, silver was used as coinage in countries around the world. Today, however, the consumption of silver has outpaced the output and the coinage has changed. [Image Gallery: Ancient Silver Playing Cards Discovered]
Sterling silver is the mostly commonly seen form of silver today. It is often used for jewelry, silverware and decorations. Sterling silver is 92.5 percent silver; the rest is copper or another metal.
Silver has interesting reflective and useful properties. It is used in mirror production and may be deposited on glass or metals. It is highly effective immediately after placement, being the best known reflector of visual light. Its power is quickly weakened, however, because silver rapidly tarnishes and loses much of its reflective properties. It is also a poor reflector of ultraviolet light.
Silver is essential to photography; photography production requires silver nitrate, or lunar caustic, compound. About 30 percent of industrial silver consumption in the United States goes toward it.
Silver is an important alloying agent. It is used in making dental, solder and brazing alloys. It is also an important component in electrical contacts, high-capacity silver-zinc, and silver-cadmium batteries. Silver paints are used in making printed circuits. Silver iodide is used in seeding clouds to produce rain.
Silver fulminate is a powerful explosive that sometimes formed while silver is being processed.
(Source: Los Alamos National Laboratory)