silver, metallic chemical element; symbol Ag [Lat. argentum]; at. no. 47; at. wt. 107.8682; m.p. 961.93°C;; b.p. 2,212°C;; sp. gr. 10.5 at 20°C;; valence +1 or +2. Pure silver is nearly white, lustrous, soft, very ductile, malleable, and an excellent conductor of heat and electricity. In many of its properties it resembles copper and gold, the elements above and below it in Group 11 of the periodic table periodic table, chart of the elements arranged according to the periodic law discovered by Dmitri I. Mendeleev and revised by Henry G. J. Moseley . In the periodic table the elements are arranged in columns and rows according to increasing atomic number (see the
..... Click the link for more information. . It is not a chemically active metal, being considerably below hydrogen in the electromotive series (see metal metal, chemical element displaying certain properties by which it is normally distinguished from a nonmetal, notably its metallic luster, the capacity to lose electrons and form a positive ion , and the ability to conduct heat and electricity.
..... Click the link for more information. ). It is, however, attacked by nitric acid (forming the nitrate) and by hot concentrated sulfuric acid. Silver is almost always monovalent in its compounds, but an oxide, a fluoride, and a sulfide of divalent silver are known. It does not oxidize in air but reacts with the hydrogen sulfide present in the air, forming silver sulfide (tarnish). Silver nitrate silver nitrate (nī`trāt), chemical compound, AgNO3, a colorless crystalline material that is very soluble in water.
..... Click the link for more information. is the most important compound. Silver chloride, bromide, and iodide are used in still photography photography, still, science and art of making permanent images on light-sensitive materials.
See also photographic processing ; motion picture photography ; motion pictures .
..... Click the link for more information. because of their sensitivity to light. Solutions of certain protein complexes containing silver are used as antiseptics. A mirror can be made by coating glass with metallic silver derived from the reaction of a solution of a silver ammonia complex with an organic reducing agent such as formaldehyde. Although silver can be found uncombined in nature, most silver used today is obtained from its ores. Among these the most important are argentite or silver glance (silver sulfide), which is found associated with other metal sulfides, e.g., galena; horn silver or cerargyrite (silver chloride); two ores composed of silver and antimony (in different proportions) called pyrargyrite (or ruby silver ore) and stephanite; and another ore composed of silver and arsenic sulfides called proustite. Mexico, the United States (Idaho, Montana, Arizona, Colorado, Utah, Nevada, California, New Mexico, and Texas), the former USSR, Peru, Australia, and Canada are the leading producers. The metal is prepared in various ways depending upon the nature of its occurrence; the greatest quantity is obtained in connection with the refining of lead and copper. It is separated from lead by the Parkes process, which is based upon the fact that silver is soluble in molten zinc whereas lead is not. The cyanide process cyanide process or cyanidation, method for extracting gold from its ore. The ore is first finely ground and may be concentrated by flotation; if it contains certain impurities, it may be roasted.
..... Click the link for more information. has largely replaced an amalgam amalgam (əmăl`gəm), alloy containing mercury .
..... Click the link for more information. process in which silver is dissolved in mercury. Some of the silver produced today is used, as in the past, in making coins (see coin coin, piece of metal, usually a disk of gold, silver, nickel, bronze, copper, aluminum, or a combination of such metals, stamped by authority of a government as a guarantee of its real or exchange value and used as money .
..... Click the link for more information. ; money money, term that actually refers to two concepts: the abstract unit of account in terms of which the value of goods, services, and obligations can be compared; and anything that is widely established as a means of payment.
..... Click the link for more information. ; bimetallism bimetallism (bīmĕt`əlĭz'əm)
..... Click the link for more information. ). Large quantities are used for silver utensils and jewelry, and in plating tableware electrolytically from a solution of sodium silver cyanide. Alloys of silver with copper, in which the copper adds hardness, are important. Coin silver is an alloy consisting of 90% silver and 10% copper. Sterling silver contains 92.5% silver and 7.5% copper. Silver alloys are used in dental amalgams and for electrical contacts. Silver was one of the first metals to be used by humans (see silverwork silverwork, utilitarian objects and works of art created from silver. Silverwork includes ecclesiastical and domestic plate, flatware, jewelry, buttons, buckles, boxes, toilet articles, weapons, furniture, and horse trappings.
..... Click the link for more information. ).
Metallic chemical element, one of the transition elements, chemical symbol Ag, atomic number 47. It is a white, lustrous precious metal, valued for its beauty. It is also valued for its electrical conductivity, which is the highest of any metal. Between copper and gold in their common group of the periodic table, it is intermediate between them in many properties. Widely distributed in nature in small amounts, as the native metal and in ores, it is usually recovered as a by-product of copper and lead production. Its use in bullion and coins was overtaken in the 1960s by demand for industrial purposes, especially photography. It is also used in printed electrical circuits, electronic conductors, and contacts. It is the catalyst for converting ethylene to ethylene oxide, the precursor of many organic chemicals. Its use in alloys in sterling (92.5% silver, 7.5% copper) and plated silverware, ornaments, and jewelry remains important; yellow gold used in jewelry is typically 25% silver, and gold dental alloys are about 10% silver. Silver dental fillings are an amalgam of silver and mercury. Silver in compounds, the most important of which is silver nitrate, has valence 1. Its chloride, bromide, and iodide are used in photography and its iodide in cloud seeding.
silver
silver [′sil·vər]
..... Click the link for more information. . It is not a chemically active metal, being considerably below hydrogen in the electromotive series (see metal metal, chemical element displaying certain properties by which it is normally distinguished from a nonmetal, notably its metallic luster, the capacity to lose electrons and form a positive ion , and the ability to conduct heat and electricity.
..... Click the link for more information. ). It is, however, attacked by nitric acid (forming the nitrate) and by hot concentrated sulfuric acid. Silver is almost always monovalent in its compounds, but an oxide, a fluoride, and a sulfide of divalent silver are known. It does not oxidize in air but reacts with the hydrogen sulfide present in the air, forming silver sulfide (tarnish). Silver nitrate silver nitrate (nī`trāt), chemical compound, AgNO3, a colorless crystalline material that is very soluble in water.
..... Click the link for more information. is the most important compound. Silver chloride, bromide, and iodide are used in still photography photography, still, science and art of making permanent images on light-sensitive materials.
See also photographic processing ; motion picture photography ; motion pictures .
..... Click the link for more information. because of their sensitivity to light. Solutions of certain protein complexes containing silver are used as antiseptics. A mirror can be made by coating glass with metallic silver derived from the reaction of a solution of a silver ammonia complex with an organic reducing agent such as formaldehyde. Although silver can be found uncombined in nature, most silver used today is obtained from its ores. Among these the most important are argentite or silver glance (silver sulfide), which is found associated with other metal sulfides, e.g., galena; horn silver or cerargyrite (silver chloride); two ores composed of silver and antimony (in different proportions) called pyrargyrite (or ruby silver ore) and stephanite; and another ore composed of silver and arsenic sulfides called proustite. Mexico, the United States (Idaho, Montana, Arizona, Colorado, Utah, Nevada, California, New Mexico, and Texas), the former USSR, Peru, Australia, and Canada are the leading producers. The metal is prepared in various ways depending upon the nature of its occurrence; the greatest quantity is obtained in connection with the refining of lead and copper. It is separated from lead by the Parkes process, which is based upon the fact that silver is soluble in molten zinc whereas lead is not. The cyanide process cyanide process or cyanidation, method for extracting gold from its ore. The ore is first finely ground and may be concentrated by flotation; if it contains certain impurities, it may be roasted.
..... Click the link for more information. has largely replaced an amalgam amalgam (əmăl`gəm), alloy containing mercury .
..... Click the link for more information. process in which silver is dissolved in mercury. Some of the silver produced today is used, as in the past, in making coins (see coin coin, piece of metal, usually a disk of gold, silver, nickel, bronze, copper, aluminum, or a combination of such metals, stamped by authority of a government as a guarantee of its real or exchange value and used as money .
..... Click the link for more information. ; money money, term that actually refers to two concepts: the abstract unit of account in terms of which the value of goods, services, and obligations can be compared; and anything that is widely established as a means of payment.
..... Click the link for more information. ; bimetallism bimetallism (bīmĕt`əlĭz'əm)
..... Click the link for more information. ). Large quantities are used for silver utensils and jewelry, and in plating tableware electrolytically from a solution of sodium silver cyanide. Alloys of silver with copper, in which the copper adds hardness, are important. Coin silver is an alloy consisting of 90% silver and 10% copper. Sterling silver contains 92.5% silver and 7.5% copper. Silver alloys are used in dental amalgams and for electrical contacts. Silver was one of the first metals to be used by humans (see silverwork silverwork, utilitarian objects and works of art created from silver. Silverwork includes ecclesiastical and domestic plate, flatware, jewelry, buttons, buckles, boxes, toilet articles, weapons, furniture, and horse trappings.
..... Click the link for more information. ).
silver
)
Dendritic (branching) silver from Ontario
(credit: Courtesy of Joseph and Helen Guetterman Collection; photograph, John H. Gerard)
silver
1.
a. a very ductile malleable brilliant greyish-white element having the highest electrical and thermal conductivity of any metal. It occurs free and in argentite and other ores: used in jewellery, tableware, coinage, electrical contacts, and in electroplating. Its compounds are used in photography. Symbol: Ag; atomic no.: 47; atomic wt.: 107.8682; valency: 1 or 2; relative density: 10.50; melting pt.: 961.93°C; boiling pt.: 2163°C
b. (as modifier): a silver coin
2. coin made of, or having the appearance of, this metal
3. Photog any of a number of silver compounds used either as photosensitive substances in emulsions or as sensitizers
4.
a. a brilliant or light greyish-white colour
b. (as adjective): silver hair
silver [′sil·vər]
(chemistry)
A white metallic transition element, symbol Ag, with atomic number 47; soluble in acids and alkalies, insoluble in water; melts at 961°C, boils at 2212°C; used in photographic chemicals, alloys, conductors, and plating.
(metallurgy)
A sonorous, ductile, malleable metal that is capable of a high degree of polish and that has high thermal and electric conductivity.
Silver
the Lone Ranger’s trusty steed. [Radio: “The Lone Ranger” in Buxton, 143–144; TV: Terrace, II, 34–35]
See : Horse
Silver
flashing white steed of the Lone Ranger. [Radio: Buxton, 143–144]
See : Whiteness
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