Description
A soft, white, ductile metallic element. Silver is widely distributed throughout the world. It occurs rarely as metallic silver (Peru, Norway) but more often as silver-gold alloys (electrum) and silver ore (galena, cerargyrite, pyrargyrite, argentite). Today silver is obtained as a byproduct in the refinement of gold, lead, copper, or zinc ores. The largest current producers of silver are Canada, Mexico, the United States, Peru, Russia, and Australia. Silver was smelted from galena as early as 3800 BCE. Another early method for refining gold or silver was called cupellation by which the ore was placed in a small cup then exposed to high heat in air; the base metals oxidized while the precious metals melted and were poured off. As a pure metal, silver is second to gold in malleability and ductility. It can be polished to a highly reflective surface. Since pure silver is too soft for many decorative items it is most often prepared as an alloy - sterling silver (925 parts silver and 75 parts copper). Alloys containing less that 90% silver cannot be stamped as silver. Silver is used for jewelry, coinage, photography, mirrors, electrical contacts, and tableware.
Synonyms and Related Terms
Ag; argentum (Lat.); Zilver (Ned.); argent (Fr.); Silber (Deut.); argento (It.); prata (Port.); plata (Esp.)
| Ag (atomic no. 47) |
| 7440-22-4 |
| 2.5 - 3.0 |
| 960.5 |
| atomic wt = 107.868 |
| 10.53 |
| 2212 |
Other Properties
Soluble in nitric acid, hot sulfuric acid, alkali cyanide solutions. Insoluble in water, alkalis. Attacked by sulfur compounds.
Isometric crystal system. Malleable and ductile. Streak = silver white. Luster = metallic. Tarnish = black, yellow, brown.
Potassium dichromate may be used for the colorimetric detection of silver in objects. It reacts with silver to form bright red silver chromate crystals.
Hazards and Safety
Inhalation of vapors is toxic. Noncombustible.
Fisher Scientific: MSDS
Additional Information
° O. Untracht, Metal Techniques for Craftsmen, Doubleday and Co., Garden City, NY, 1968.
° Mineralogy Database: Silver
° Web Elements: Website
|
Last updated on: 6/28/2009 11:21:13 AM
|
|
 |
|
