Silver: Precious Metal With The Highest Thermal And Electrical ConductivitySilver is generally described as a soft, white, lustrous metallic chemical element. It occurs naturally in its pure form, as an alloy with other metallic elements (especially gold), and in chlorargyrite and other minerals. As one of three coinage metals (the other two being copper and gold), silver is very malleable and ductile. Of the different metals, silver is known to have the highest thermal conductivity. Similarly of the different known elements, silver has the highest electrical conductivity. Provided below are some of the properties of this precious metal. General: • Chemical Symbol: Ag • Atomic Number: 47 • Category (as an element): Transition Metal • Group/ Period/ Block (in the Periodic Table): 11/ 5/ d • Atomic Weight: 107.8682 g.mol-1 • Electron Configuration: [Kr] 4d10 5s1 Physical: • Density (near room temperature): 10.49 g.cm-3 • Liquid Density (at melting point): 9.320 g.cm-3 • Melting Point: 961.78°C, 1234.93°F, 2041.4°K • Boiling Point: 2162°C, 3924°F, 2435°K • Heat of Fusion: 11.28 kJ.mol-1 • Heat of Vaporization: 250.58 kJ.mol-1 Atomic: • Oxidation States: 1, 2, 3 • Electronegativity: 1.93 (Pauling scale) • Atomic Radius: 144 picometre • Covalent Radius: 145±5 picometre • Van der Waals Radius: 172 picometre • Ionization Energies: 731 kJ.mol-1 (first), 2070 kJ.mol-1 (second), 3361 kJ.mol-1 (third) Despite having higher electrical conductivity than copper, silver isn't as much used for electrical purposes as copper is. There are two reasons for this: first is that silver has a greater tendency to tarnish; and second is that silver is much more expensive. As a precious metal, silver has been much valued for ages with its so many applications, as in the following: 1. Jewelry (sterling silver is used in making fine jewelry and watches). 2. Silverware (sterling silver is also used in making utensils, tableware and ornaments). 3. Photography (silver nitrate and silver halides are used in making films). 4. Electrical and electronic products (silver paints are used in making printed circuits; silver electrical contacts are used in making computer keyboards). 5. Dentistry (silver-mercury alloy is used in making dental amalgams). 6. Optics and mirrors. 7. Various industrial and commercial uses (silver is ideal for use as a catalyst in chemical reactions). 8. Clothing (silver ions are mixed with the polymer to make yarns). 9. Medicine (silver compounds and silver ions have toxic effect on some viruses, fungi and bacteria, but not on humans). 10. Currency or coinage (as in silver bullion). The principal sources of silver are copper, lead, zinc and gold ores. It also occurs in the minerals chlorargyrite and argentite. Of course, silver occurs natively, too. Some of the top silver-producing countries in the world are the United States, Canada, Peru, and Mexico. Fine silver, which has no less than 99.9% silver, is available commercially. Because of competing store-of-value and industrial demands, the price of silver has fluctuated considerably over the last century. As of the beginning of 2010, the price of this precious metal is estimated at about 18 U.S. dollars per troy ounce (or 588 U.S. dollars per kilogram).
precious metals,gold,silver,platinum,ruthenium,rhenium,palladium,osmium Articles
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