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Silver is a ; it has symbol Ag (, derived from Proto-Indo-European )) and 47. A soft, white, lustrous , it exhibits the highest electrical conductivity, thermal conductivity, and of any .

(2004). 9780080545233, Academic Press. .
The metal is found in the Earth's crust in the pure, free elemental form (" silver"), as an with and other metals, and in minerals such as and . Most silver is produced as a byproduct of , gold, , and refining.

Silver has long been valued as a . Silver metal is used in many , sometimes : while it is more abundant than gold, it is much less abundant as a . Its purity is typically measured on a basis; a 94%-pure alloy is described as "0.940 fine". As one of the seven metals of antiquity, silver has had an enduring role in most human cultures.

Other than in and as an medium ( and ), silver is used in , , , ornaments, high-value tableware and utensils (hence the term "silverware"), in electrical contacts and conductors, in specialized mirrors, window coatings, in of chemical reactions, as a colorant in , and in specialized confectionery. Its compounds are used in photographic and film. Dilute solutions of and other silver compounds are used as and microbiocides (oligodynamic effect), added to , wound-dressings, , and other medical instruments.


Characteristics
Silver is similar in its physical and chemical properties to its two vertical neighbours in group 11 of the : , and . Its 47 electrons are arranged in the configuration Kr4d105s1, similarly to copper (Ar3d104s1) and gold (Xe4f145d106s1); group 11 is one of the few groups in the which has a completely consistent set of electron configurations. This distinctive electron configuration, with a single electron in the highest occupied s over a filled d subshell, accounts for many of the singular properties of metallic silver.

Silver is a relatively soft and extremely and , though it is slightly less malleable than gold. Silver crystallizes in a face-centered cubic lattice with bulk coordination number 12, where only the single 5s electron is delocalized, similarly to copper and gold.Greenwood and Earnshaw, p. 1178 Unlike metals with incomplete d-shells, metallic bonds in silver are lacking a character and are relatively weak. This observation explains the low and high ductility of of silver.

(1992). 9783527281268, VCH Publishers. .

Silver has a brilliant, white, metallic luster that can take a high ,

(2024). 9781600591310, Sterling Publishing Company, Inc..
and which is so characteristic that the name of the metal itself has become a color name.Greenwood and Earnshaw, p. 1177 Protected silver has greater optical than at all wavelengths longer than ~450 nm. At wavelengths shorter than 450 nm, silver's reflectivity is inferior to that of aluminium and drops to zero near 310 nm.

Very high electrical and thermal conductivity are common to the elements in group 11, because their single s electron is free and does not interact with the filled d subshell, as such interactions (which occur in the preceding transition metals) lower electron mobility.

(2024). 9780471649526, John Wiley & Sons.
The thermal conductivity of silver is among the highest of all materials, although the thermal conductivity of (in the ) and superfluid helium-4 are higher.
(2024). 9780849304859, CRC press. .
The electrical conductivity of silver is the highest of all metals, greater even than copper. Silver also has the lowest contact resistance of any metal. Silver is rarely used for its electrical conductivity, due to its high cost, although an exception is in radio-frequency engineering, particularly at and higher frequencies where silver plating improves electrical conductivity because those rather than through the interior. During World War II in the US, tons of silver were used for the in for enriching , mainly because of the wartime shortage of copper.
(1987). 9780688069100, Morrow.

Silver readily forms with copper, gold, and . Zinc-silver alloys with low zinc concentration may be considered as face-centred cubic solid solutions of zinc in silver, as the structure of the silver is largely unchanged while the electron concentration rises as more zinc is added. Increasing the electron concentration further leads to body-centred cubic (electron concentration 1.5), complex cubic (1.615), and hexagonal close-packed phases (1.75).


Isotopes
Naturally occurring silver is composed of two stable , 107Ag and 109Ag, with 107Ag being slightly more abundant (51.839% natural abundance). This almost equal abundance is rare in the periodic table. The is 107.8682(2) u; this value is very important because of the importance of silver compounds, particularly halides, in gravimetric analysis. Both isotopes of silver are produced in stars via the (slow neutron capture), as well as in supernovas via the (rapid neutron capture).

Twenty-eight have been characterized, the most stable being 105Ag with a of 41.29 days, 111Ag with a half-life of 7.45 days, and 112Ag with a half-life of 3.13 hours. Silver has numerous , the most stable being 108mAg ( t1/2 = 418 years), 110mAg ( t1/2 = 249.79 days) and 106mAg ( t1/2 = 8.28 days). All of the remaining isotopes have half-lives of less than an hour, and the majority of these have half-lives of less than three minutes.

Isotopes of silver range in from 92.950 u (93Ag) to 129.950 u (130Ag); the primary before the most abundant stable isotope, 107Ag, is and the primary mode after is . The primary before 107Ag are (element 46) isotopes, and the primary products after are (element 48) isotopes.

The palladium 107Pd decays by beta emission to 107Ag with a half-life of 6.5 million years. are the only objects with a high-enough palladium-to-silver ratio to yield measurable variations in 107Ag abundance. 107Ag was first discovered in the Santa Clara meteorite in 1978. 107Pd–107Ag correlations observed in bodies that have clearly been melted since the accretion of the must reflect the presence of unstable nuclides in the early Solar System.


Chemistry
+ Oxidation states and stereochemistries of silver
Ag(CO)3
Ag(CN)2
AgI(PEt2Ar)2
Ag(diars)2+
AgF, AgCl, AgBr
Ag(py)42+
AgF4
AgF63−
Silver is a rather unreactive metal. This is because its filled 4d shell is not very effective in shielding the electrostatic forces of attraction from the nucleus to the outermost 5s electron, and hence silver is near the bottom of the electrochemical series ( E0(Ag+/Ag) = +0.799 V). In group 11, silver has the lowest first ionization energy (showing the instability of the 5s orbital), but has higher second and third ionization energies than copper and gold (showing the stability of the 4d orbitals), so that the chemistry of silver is predominantly that of the +1 oxidation state, reflecting the increasingly limited range of oxidation states along the transition series as the d-orbitals fill and stabilize.Greenwood and Earnshaw, p. 1180 Unlike , for which the larger of Cu2+ as compared to Cu+ is the reason why the former is the more stable in aqueous solution and solids despite lacking the stable filled d-subshell of the latter, with silver this effect is swamped by its larger second ionisation energy. Hence, Ag+ is the stable species in aqueous solution and solids, with Ag2+ being much less stable as it oxidizes water.

Most silver compounds have significant character due to the small size and high first ionization energy (730.8 kJ/mol) of silver. Furthermore, silver's Pauling electronegativity of 1.93 is higher than that of (1.87), and its electron affinity of 125.6 kJ/mol is much higher than that of (72.8 kJ/mol) and not much less than that of (141.0 kJ/mol).Greenwood and Earnshaw, p. 1176 Due to its full d-subshell, silver in its main +1 oxidation state exhibits relatively few properties of the transition metals proper from groups 4 to 10, forming rather unstable organometallic compounds, forming linear complexes showing very low coordination numbers like 2, and forming an amphoteric oxideLidin RA 1996, Inorganic substances handbook, Begell House, New York, . p. 5 as well as like the post-transition metals.Goodwin F, Guruswamy S, Kainer KU, Kammer C, Knabl W, Koethe A, Leichtfreid G, Schlamp G, Stickler R & Warlimont H 2005, 'Noble metals and noble metal alloys', in Springer Handbook of Condensed Matter and Materials Data, W Martienssen & H Warlimont (eds), Springer, Berlin, pp. 329–406, . p. 341 Unlike the preceding transition metals, the +1 oxidation state of silver is stable even in the absence of .

Silver does not react with air, even at red heat, and thus was considered by as a , along with gold. Its reactivity is intermediate between that of copper (which forms copper(I) oxide when heated in air to red heat) and gold. Like copper, silver reacts with and its compounds; in their presence, silver tarnishes in air to form the black (copper forms the green instead, while gold does not react). While silver is not attacked by non-oxidizing acids, the metal dissolves readily in hot concentrated , as well as dilute or concentrated . In the presence of air, and especially in the presence of hydrogen peroxide, silver dissolves readily in aqueous solutions of .Greenwood and Earnshaw, p. 1179

The three main forms of deterioration in historical silver artifacts are tarnishing, formation of due to long-term immersion in salt water, as well as reaction with ions or oxygen. Fresh silver chloride is pale yellow, becoming purplish on exposure to light; it projects slightly from the surface of the artifact or coin. The precipitation of copper in ancient silver can be used to date artifacts, as copper is nearly always a constituent of silver alloys. "Silver Artifacts" in Corrosion – Artifacts. NACE Resource Center

Silver metal is attacked by strong oxidizers such as potassium permanganate () and potassium dichromate (), and in the presence of potassium bromide (). These compounds are used in photography to silver images, converting them to silver bromide that can either be fixed with or redeveloped to intensify the original image. Silver forms complexes () that are soluble in water in the presence of an excess of cyanide ions. Silver cyanide solutions are used in of silver.

(1995). 9783540586197, Springer. .

The common of silver are (in order of commonness): +1 (the most stable state; for example, , AgNO3); +2 (highly oxidising; for example, silver(II) fluoride, AgF2); and even very rarely +3 (extreme oxidising; for example, potassium tetrafluoroargentate(III), KAgF4). The +3 state requires very strong oxidising agents to attain, such as or , and some silver(III) compounds react with atmospheric moisture and attack glass.Greenwood and Earnshaw, p. 1188 Indeed, silver(III) fluoride is usually obtained by reacting silver or silver monofluoride with the strongest known oxidizing agent, krypton difluoride.Greenwood and Earnshaw, p. 903


Compounds

Oxides and chalcogenides
Silver and gold have rather low chemical affinities for oxygen, lower than copper, and it is therefore expected that silver oxides are thermally quite unstable. Soluble silver(I) salts precipitate dark-brown silver(I) oxide, Ag2O, upon the addition of alkali. (The hydroxide AgOH exists only in solution; otherwise it spontaneously decomposes to the oxide.) Silver(I) oxide is very easily reduced to metallic silver, and decomposes to silver and oxygen above 160 °C.Greenwood and Earnshaw, pp. 1181–82 This and other silver(I) compounds may be oxidized by the strong oxidizing agent to black AgO, a mixed silver(I,III) oxide of formula AgIAgIIIO2. Some other mixed oxides with silver in non-integral oxidation states, namely Ag2O3 and Ag3O4, are also known, as is Ag3O which behaves as a metallic conductor.

Silver(I) sulfide, Ag2S, is very readily formed from its constituent elements and is the cause of the black tarnish on some old silver objects. It may also be formed from the reaction of with silver metal or aqueous Ag+ ions. Many non-stoichiometric and tellurides are known; in particular, AgTe~3 is a low-temperature .


Halides
The only known dihalide of silver is the difluoride, AgF2, which can be obtained from the elements under heat. A strong yet thermally stable and therefore safe fluorinating agent, silver(II) fluoride is often used to synthesize hydrofluorocarbons.Greenwood and Earnshaw, pp. 1183–85

In stark contrast to this, all four silver(I) halides are known. The fluoride, , and have the sodium chloride structure, but the has three known stable forms at different temperatures; that at room temperature is the cubic structure. They can all be obtained by the direct reaction of their respective elements. As the halogen group is descended, the silver halide gains more and more covalent character, solubility decreases, and the colour changes from the white chloride to the yellow iodide as the energy required for ligand-metal charge transfer (XAg+ → XAg) decreases. The fluoride is anomalous, as the fluoride ion is so small that it has a considerable energy and hence is highly water-soluble and forms di- and tetrahydrates. The other three silver halides are highly insoluble in aqueous solutions and are very commonly used in gravimetric methods. All four are (though the monofluoride is so only to light), especially the bromide and iodide which photodecompose to silver metal, and thus were used in traditional photography. The reaction involved is:Greenwood and Earnshaw, pp. 1185–87

X + → X + e (excitation of the halide ion, which gives up its extra electron into the conduction band)
Ag+ + e → Ag (liberation of a silver ion, which gains an electron to become a silver atom)

The process is not reversible because the silver atom liberated is typically found at a or an impurity site, so that the electron's energy is lowered enough that it is "trapped".


Other inorganic compounds
White , AgNO3, is a versatile precursor to many other silver compounds, especially the halides, and is much less sensitive to light. It was once called lunar caustic because silver was called luna by the ancient alchemists, who believed that silver was associated with the Moon. It is often used for gravimetric analysis, exploiting the insolubility of the heavier silver halides which it is a common precursor to. Silver nitrate is used in many ways in organic synthesis, e.g. for and oxidations. Ag+ binds reversibly, and silver nitrate has been used to separate mixtures of alkenes by selective absorption. The resulting can be decomposed with to release the free alkene.

Yellow , Ag2CO3 can be easily prepared by reacting aqueous solutions of with a deficiency of silver nitrate. Its principal use is for the production of silver powder for use in microelectronics. It is reduced with , producing silver free of alkali metals:Brumby et al.

Ag2CO3 + CH2O → 2 Ag + 2 CO2 + H2

Silver carbonate is also used as a in organic synthesis such as the Koenigs–Knorr reaction. In the Fétizon oxidation, silver carbonate on acts as an to form from . It is also employed to convert bromides into alcohols.

, AgCNO, a powerful, touch-sensitive used in , is made by reaction of silver metal with nitric acid in the presence of . Other dangerously explosive silver compounds are , AgN3, formed by reaction of silver nitrate with ,

(2024). 9783527316564, Wiley–VCH. .
and , Ag2C2, formed when silver reacts with gas in ammonia solution. In its most characteristic reaction, silver azide decomposes explosively, releasing nitrogen gas: given the photosensitivity of silver salts, this behaviour may be induced by shining a light on its crystals.

2 (s) → 3 (g) + 2 Ag (s)


Coordination compounds
Silver complexes tend to be similar to those of its lighter homologue copper. Silver(III) complexes tend to be rare and very easily reduced to the more stable lower oxidation states, though they are slightly more stable than those of copper(III). For instance, the square planar periodate Ag(IO5OH)25− and tellurate Ag{TeO4(OH)2}25− complexes may be prepared by oxidising silver(I) with alkaline . The yellow diamagnetic AgF4 is much less stable, fuming in moist air and reacting with glass.

Silver(II) complexes are more common. Like the valence isoelectronic copper(II) complexes, they are usually square planar and paramagnetic, which is increased by the greater field splitting for 4d electrons than for 3d electrons. Aqueous Ag2+, produced by oxidation of Ag+ by ozone, is a very strong oxidising agent, even in acidic solutions: it is stabilized in due to complex formation. Peroxodisulfate oxidation is generally necessary to give the more stable complexes with heterocyclic , such as Ag(py)42+ and Ag(bipy)22+: these are stable provided the counterion cannot reduce the silver back to the +1 oxidation state. AgF42− is also known in its violet barium salt, as are some silver(II) complexes with N- or O-donor ligands such as pyridine carboxylates.Greenwood and Earnshaw, p. 1189

By far the most important oxidation state for silver in complexes is +1. The Ag+ cation is diamagnetic, like its homologues Cu+ and Au+, as all three have closed-shell electron configurations with no unpaired electrons: its complexes are colourless provided the ligands are not too easily polarized such as I. Ag+ forms salts with most anions, but it is reluctant to coordinate to oxygen and thus most of these salts are insoluble in water: the exceptions are the nitrate, perchlorate, and fluoride. The tetracoordinate tetrahedral aqueous ion Ag(H2O)4+ is known, but the characteristic geometry for the Ag+ cation is 2-coordinate linear. For example, silver chloride dissolves readily in excess aqueous ammonia to form Ag(NH3)2+; silver salts are dissolved in photography due to the formation of the thiosulfate complex Ag(S2O3)23−; and extraction for silver (and gold) works by the formation of the complex Ag(CN)2. Silver cyanide forms the linear polymer {Ag–C≡N→Ag–C≡N→}; silver has a similar structure, but forms a zigzag instead because of the sp3-hybridized sulfur atom. are unable to form linear complexes and thus silver(I) complexes with them tend to form polymers; a few exceptions exist, such as the near-tetrahedral and complexes Ag(L–L)2+.Greenwood and Earnshaw, pp. 1195–96


Organometallic
Under standard conditions, silver does not form simple carbonyls, due to the weakness of the Ag–C bond. A few are known at very low temperatures around 6–15 K, such as the green, planar paramagnetic Ag(CO)3, which dimerizes at 25–30 K, probably by forming Ag–Ag bonds. Additionally, the silver carbonyl Ag(CO) B(OTeF5)4 is known. Polymeric AgLX complexes with and are known, but their bonds are thermodynamically weaker than even those of the complexes (though they are formed more readily than those of the analogous gold complexes): they are also quite unsymmetrical, showing the weak π bonding in group 11. Ag–C σ bonds may also be formed by silver(I), like copper(I) and gold(I), but the simple alkyls and aryls of silver(I) are even less stable than those of copper(I) (which tend to explode under ambient conditions). For example, poor thermal stability is reflected in the relative decomposition temperatures of AgMe (−50 °C) and CuMe (−15 °C) as well as those of PhAg (74 °C) and PhCu (100 °C).Greenwood and Earnshaw, pp. 1199–200

The C–Ag bond is stabilized by ligands, for example in AgCF(CF3)2. Alkenylsilver compounds are also more stable than their alkylsilver counterparts. Silver-NHC complexes are easily prepared, and are commonly used to prepare other NHC complexes by displacing labile ligands. For example, the reaction of the bis(NHC)silver(I) complex with bis(acetonitrile)palladium dichloride or chlorido(dimethyl sulfide)gold(I):


Intermetallic
Silver forms with most other elements on the periodic table. The elements from groups 1–3, except for , , and , are very miscible with silver in the condensed phase and form intermetallic compounds; those from groups 4–9 are only poorly miscible; the elements in groups 10–14 (except and ) have very complex Ag–M phase diagrams and form the most commercially important alloys; and the remaining elements on the periodic table have no consistency in their Ag–M phase diagrams. By far the most important such alloys are those with copper: most silver used for coinage and jewellery is in reality a silver–copper alloy, and the is used in vacuum . The two metals are completely miscible as liquids but not as solids; their importance in industry comes from the fact that their properties tend to be suitable over a wide range of variation in silver and copper concentration, although most useful alloys tend to be richer in silver than the eutectic mixture (71.9% silver and 28.1% copper by weight, and 60.1% silver and 28.1% copper by atom).Brumby et al., pp. 54–61

Most other binary alloys are of little use: for example, silver–gold alloys are too soft and silver– alloys too toxic. Ternary alloys have much greater importance: dental amalgams are usually silver–tin–mercury alloys, silver–copper–gold alloys are very important in jewellery (usually on the gold-rich side) and have a vast range of hardnesses and colours, silver–copper–zinc alloys are useful as low-melting brazing alloys, and silver–cadmium– (involving three adjacent elements on the periodic table) is useful in because of its high thermal neutron capture cross-section, good conduction of heat, mechanical stability, and resistance to corrosion in hot water.


Etymology
The word silver appears in in various spellings, such as seolfor and siolfor. It is with Old High German silabar; silubr; or silfr, all ultimately deriving from Proto-Germanic *silubra. The Balto-Slavic words for silver are rather similar to the Germanic ones (e.g. серебро , srebro, Lithuanian sidãbras), as is the form silabur. They may have a common Indo-European origin, although their morphology rather suggest a non-Indo-European .
(2024). 9789004183407, Brill. .
(2024). 9780199287918, Oxford University Press. .
Some scholars have thus proposed a Paleo-Hispanic origin, pointing to the form zilharr as an evidence.

The chemical symbol Ag is from the word for silver, argentum (compare ἄργυρος, ), from the Proto-Indo-European root * h₂erǵ- (formerly reconstructed as *arǵ-), meaning or . This was the usual Proto-Indo-European word for the metal, whose reflexes are missing in Germanic and Balto-Slavic.


History
Silver was known in prehistoric times:Weeks, p. 4 the three metals of group 11, copper, silver, and gold, occur in the in nature and were probably used as the first primitive forms of as opposed to simple bartering.Greenwood and Earnshaw, pp. 1173–74 However, unlike copper, silver did not lead to the growth of on account of its low structural strength, and was more often used ornamentally or as money.
(2024). 9781615038213, ASM International.
Since silver is more reactive than gold, supplies of native silver were much more limited than those of gold. For example, silver was more expensive than gold in Egypt until around the fifteenth century BC:Weeks, pp. 14–19 the Egyptians are thought to have separated gold from silver by heating the metals with salt, and then reducing the produced to the metal.

The situation changed with the discovery of , a technique that allowed silver metal to be extracted from its ores. While heaps found in and on the islands of the indicate that silver was being separated from as early as the 4th millennium BC, and one of the earliest silver extraction centres in Europe was in the early Chalcolithic period,

(2024). 9783944507057, Landesamt für Denkmalpflege und Archäologie Sachsen-Anhalt. .
these techniques did not spread widely until later, when it spread throughout the region and beyond. The origins of silver production in , , and were almost certainly equally ancient, but are not well-documented due to their great age.

When the first came to what is now , they obtained so much silver that they could not fit it all on their ships, and as a result used silver to weight their anchors instead of lead. By the time of the Greek and Roman civilizations, silver coins were a staple of the economy: the Greeks were already extracting silver from by the 7th century BC, and the rise of was partly made possible by the nearby silver mines at , from which they extracted about 30 tonnes a year from 600 to 300 BC.

(2024). 9780199605637, Oxford University Press.
The stability of the relied to a high degree on the supply of silver bullion, mostly from Spain, which produced on a scale unparalleled before the discovery of the New World. Reaching a peak production of 200 tonnes per year, an estimated silver stock of 10,000 tonnes circulated in the in the middle of the second century AD, five to ten times larger than the combined amount of silver available to medieval Europe and the Abbasid Caliphate around AD 800. The Romans also recorded the extraction of silver in central and northern Europe in the same time period. This production came to a nearly complete halt with the fall of the Roman Empire, not to resume until the time of : by then, tens of thousands of tonnes of silver had already been extracted.Brumby et al., pp. 16–19

Central Europe became the centre of silver production during the , as the Mediterranean deposits exploited by the ancient civilisations had been exhausted. Silver mines were opened in , , , the region, , , , , , , and the southern . Most of these ores were quite rich in silver and could simply be separated by hand from the remaining rock and then smelted; some deposits of native silver were also encountered. Many of these mines were soon exhausted, but a few of them remained active until the Industrial Revolution, before which the world production of silver was around a meagre 50 tonnes per year. In the Americas, high temperature silver-lead technology was developed by pre-Inca civilizations as early as AD 60–120; silver deposits in India, China, Japan, and pre-Columbian America continued to be mined during this time.

With the discovery of America and the plundering of silver by the Spanish conquistadors, Central and South America became the dominant producers of silver until around the beginning of the 18th century, particularly , , , and : the last of these countries later took its name from that of the metal that composed so much of its mineral wealth. The silver trade gave way to a global network of exchange. As one historian put it, silver "went round the world and made the world go round."

(1998). 9780520214743, University of California Press. .
Much of this silver ended up in the hands of the Chinese. A Portuguese merchant in 1621 noted that silver "wanders throughout all the world... before flocking to China, where it remains as if at its natural center." Still, much of it went to Spain, allowing Spanish rulers to pursue military and political ambitions in both Europe and the Americas. "New World mines", concluded several historians, "supported the Spanish empire."

In the 19th century, primary production of silver moved to North America, particularly , , and in the : some secondary production from lead and zinc ores also took place in Europe, and deposits in and the Russian Far East as well as in were mined. emerged as an important producer during the 1970s after the discovery of copper deposits that were rich in silver, before the centre of production returned to the Americas the following decade. Today, Peru and Mexico are still among the primary silver producers, but the distribution of silver production around the world is quite balanced and about one-fifth of the silver supply comes from recycling instead of new production.

File:Proto-Elamite kneeling bull holding a spouted vessel.jpg| kneeling bull holding a spouted vessel; 3100–2900 BC; 16.3×6.3×10.8 cm; Metropolitan Museum of Art (New York City) Horus as falcon god with Egyptian crown from the 27th dynasty (05).jpg| figurine of as falcon god with an Egyptian crown; ; silver and ; height: 26.9 cm; Staatliche Sammlung für Ägyptische Kunst (, Germany) Silver tetradrachm MET DP139641.jpg| ; 315–308 BC; diameter: 2.7 cm; Metropolitan Museum of Art Silver-gilt bowl MET DP105813.jpg|Ancient Greek gilded bowl; 2nd–1st century BC; height: 7.6 cm, dimeter: 14.8 cm; Metropolitan Museum of Art Silver plate MET DP231273.jpg| plate; 1st–2nd century AD; height: 0.1 cm, diameter: 12.7 cm; Metropolitan Museum of Art Silver bust of Serapis MET DT6658.jpg|Roman bust of ; 2nd century; 15.6×9.5 cm; Metropolitan Museum of Art Schaal met voorstellingen uit de geschiedenis van Diana en Actaeon door Paulus Willemsz van Vianen in 1613.jpg| basin with scenes from the story of Diana and Actaeon; 1613; length: 50 cm, height: 6 cm, width: 40 cm; (, the ) Silver Tureen (a), lid (b) -pair with 1975.1.2560a-c- MET SLP2561a b-1.jpg|French tureen; 1749; height: 26.3 cm, width: 39 cm, depth: 24 cm; Metropolitan Museum of Art Coffeepot MET DP103144 (cropped),.jpg|French Rococo coffeepot; 1757; height: 29.5 cm; Metropolitan Museum of Art Ewer MET DT236853.jpg|French ewer; 1784–1785; height: 32.9 cm; Metropolitan Museum of Art Elkington & Co. - Neo-Rococo Coffee Pot - 2003.243 - Cleveland Museum of Art.jpg| coffeepot; 1845; overall: 32×23.8×15.4 cm; Cleveland Museum of Art (, , US) Dessert Spoon (France), ca. 1890 (CH 18653899-2).jpg|French dessert spoons; circa 1890; Cooper Hewitt, Smithsonian Design Museum (New York City) Jardiniere And Liner (Germany), ca. 1905–10 (CH 18444035) (cropped).jpg|Art Nouveau jardinière; circa 1905–1910; height: 22 cm, width: 47 cm, depth: 22.5 cm; Cooper Hewitt, Smithsonian Design Museum Handspiegel met gedreven Jugendstilornament, BK-1967-10.jpg|Hand mirror; 1906; height: 20.7 cm, weight: 88 g; (, the ) Mystery watch.jpg|; ca. 1889; diameter: 5.4 cm, depth: 1.8 cm; Musée d'Horlogerie of Le Locle ()


Symbolic role
Silver plays a certain role in mythology and has found various usage as a metaphor and in folklore. The Greek poet 's Works and Days (lines 109–201) lists different ages of man named after metals like gold, silver, bronze and iron to account for successive ages of humanity. 's contains another retelling of the story, containing an illustration of silver's metaphorical use of signifying the second-best in a series, better than bronze but worse than gold:

In folklore, silver was commonly thought to have mystic powers: for example, a is often supposed in such folklore the only weapon that is effective against a , , or other .

(1995). 9781853488887, Devizes, Quintet Publishing.
9789543042326, ЕИ "LiterNet". .
(2024). 9781473630819, John Murray.
From this the idiom of a developed into figuratively referring to any simple solution with very high effectiveness or almost miraculous results, as in the widely discussed software engineering paper "No Silver Bullet." Other powers attributed to silver include detection of poison and facilitation of passage into the .

Silver production has also inspired figurative language. Clear references to cupellation occur throughout the of the , such as in 's rebuke to Judah: "The bellows are burned, the lead is consumed of the fire; the founder melteth in vain: for the wicked are not plucked away. Reprobate silver shall men call them, because the Lord hath rejected them." (Jeremiah 6:19–20) Jeremiah was also aware of sheet silver, exemplifying the malleability and ductility of the metal: "Silver spread into plates is brought from Tarshish, and gold from Uphaz, the work of the workman, and of the hands of the founder: blue and purple is their clothing: they are all the work of cunning men." (Jeremiah 10:9)

Silver also has more negative cultural meanings: the idiom , referring to a reward for betrayal, references the bribe is said in the to have taken from Jewish leaders in to turn over to soldiers of the high priest Caiaphas. Ethically, silver also symbolizes greed and degradation of consciousness; this is the negative aspect, the perverting of its value.

(2024). 9789734612864, Polirom.


Occurrence and production
The abundance of silver in the Earth's crust is 0.08 parts per million, almost exactly the same as that of mercury. It mostly occurs in ores, especially and , Ag2S. Argentite deposits sometimes also contain silver when they occur in reducing environments, and when in contact with salt water they are converted to (including ), AgCl, which is prevalent in and New South Wales.Greenwood and Earnshaw, pp. 1174–67 Most other silver minerals are silver or ; they are generally lustrous semiconductors. Most true silver deposits, as opposed to argentiferous deposits of other metals, came from vulcanism.Brumby et al., pp. 21–22

The principal sources of silver are the ores of copper, copper-nickel, lead, and lead-zinc obtained from , , , , , , and . Peru, Bolivia and Mexico have been mining silver since 1546, and are still major world producers. Top silver-producing mines are (Australia), Fresnillo (Mexico), San Cristóbal (Bolivia), (Peru), (Poland), and Penasquito (Mexico).

(2024). 9780982674147, Euromoney Books.
Top near-term mine development projects through 2015 are Pascua Lama (Chile), Navidad (Argentina), Jaunicipio (Mexico), Malku Khota (Bolivia), and Hackett River (Canada). In , Tajikistan is known to have some of the largest silver deposits in the world.

Silver is usually found in nature combined with other metals, or in minerals that contain silver compounds, generally in the form of such as (lead sulfide) or (lead carbonate). So the primary production of silver requires the smelting and then of argentiferous lead ores, a historically important process.Kassianidou, V. (2003). "Early Extraction of Silver from Complex Polymetallic Ores", pp. 198–206 in Craddock, P.T. and Lang, J (eds.) Mining and Metal production through the Ages. London, British Museum Press. Lead melts at 327 °C, lead oxide at 888 °C and silver melts at 960 °C. To separate the silver, the alloy is melted again at the high temperature of 960 °C to 1000 °C in an oxidizing environment. The lead oxidises to lead monoxide, then known as , which captures the oxygen from the other metals present. The liquid lead oxide is removed or absorbed by into the hearth linings.Craddock, P.T. (1995). Early metal mining and production. Edinburgh: Edinburgh University Press. p. 223. Bayley, J., Crossley, D. and Ponting, M. (eds). (2008). Metals and Metalworking. A research framework for archaeometallurgy Https://www.academia.edu/7001043/Late_Uruk_silver_production_by_cupellation_at_Habuba_Kabira_Syria_Pernicka_et_al_1998_ "Late Uruk silver production by cupellation at Habuba Kabira, Syria", pp. 123–34 in Metallurgica Antiqua, Deutsches Bergbau-Museum.

(s) + 2(s) + (g) → 2(absorbed) + Ag(l)

Today, silver metal is primarily produced instead as a secondary byproduct of electrolytic refining of copper, lead, and zinc, and by application of the on lead bullion from ore that also contains silver. In such processes, silver follows the non-ferrous metal in question through its concentration and smelting, and is later purified out. For example, in copper production, purified copper is deposited on the cathode, while the less reactive precious metals such as silver and gold collect under the anode as the so-called "anode slime". This is then separated and purified of base metals by treatment with hot aerated dilute acid and heating with lime or silica flux, before the silver is purified to over 99.9% purity via electrolysis in solution.

Commercial-grade fine silver is at least 99.9% pure, and purities greater than 99.999% are available. In 2022, Mexico was the top producer of silver (6,300 or 24.2% of the world's total of 26,000 t), followed by China (3,600 t) and Peru (3,100 t).


In marine environments
Silver concentration is low in (pmol/L). Levels vary by depth and between water bodies. Dissolved silver concentrations range from 0.3 pmol/L in coastal surface waters to 22.8 pmol/L in pelagic deep waters. Analyzing the presence and dynamics of silver in marine environments is difficult due to these particularly low concentrations and complex interactions in the environment. Although a rare trace metal, concentrations are greatly impacted by fluvial, aeolian, atmospheric, and upwelling inputs, as well as anthropogenic inputs via discharge, waste disposal, and emissions from industrial companies. Other internal processes such as decomposition of organic matter may be a source of dissolved silver in deeper waters, which feeds into some surface waters through upwelling and vertical mixing.

In the Atlantic and Pacific, silver concentrations are minimal at the surface but rise in deeper waters. Silver is taken up by plankton in the photic zone, remobilized with depth, and enriched in deep waters. Silver is transported from the Atlantic to the other oceanic water masses. In North Pacific waters, silver is remobilized at a slower rate and increasingly enriched compared to deep Atlantic waters. Silver has increasing concentrations that follow the major oceanic conveyor belt that cycles water and nutrients from the North Atlantic to the South Atlantic to the North Pacific.

There is not an extensive amount of data focused on how marine life is affected by silver despite the likely deleterious effects it could have on organisms through , association with particulate matters, and . Not until about 1984 did scientists begin to understand the chemical characteristics of silver and the potential toxicity. In fact, mercury is the only other trace metal that surpasses the toxic effects of silver; however, the full extent of silver toxicity is not expected in oceanic conditions because of its ability to transfer into nonreactive biological compounds.

In one study, the presence of excess ionic silver and silver caused bioaccumulation effects on zebrafish organs and altered the chemical pathways within their gills. In addition, very early experimental studies demonstrated how the toxic effects of silver fluctuate with salinity and other parameters, as well as between life stages and different species such as finfish, molluscs, and crustaceans. Another study found raised concentrations of silver in the muscles and liver of dolphins and whales, indicating pollution of this metal within recent decades. Silver is not an easy metal for an organism to eliminate and elevated concentrations can cause death.


Monetary use
The earliest known coins were minted in the kingdom of in around 600 BC. The coins of Lydia were made of , which is a naturally occurring of gold and silver, that was available within the territory of Lydia. Since that time, , in which the standard economic unit of account is a fixed weight of silver, have been widespread throughout the world until the 20th century. Notable through the centuries include the , the Roman ,Crawford, Michael H. (1974). Roman Republican Coinage, Cambridge University Press, 2 Volumes. the Islamic , Oxford English Dictionary, 1st edition, s.v. 'dirhem' the from ancient India and from the time of the (grouped with copper and gold coins to create a trimetallic standard), and the .
(2024). 9781118292174, John Wiley & Sons. .

The ratio between the amount of silver used for coinage and that used for other purposes has fluctuated greatly over time; for example, in wartime, more silver tends to have been used for coinage to finance the war.Brumby et al., pp. 63–65

Today, silver bullion has the ISO 4217 currency code XAG, one of only four to have one (the others being , , and gold). Silver coins are produced from cast rods or ingots, rolled to the correct thickness, heat-treated, and then used to cut from. These blanks are then milled and minted in a coining press; modern coining presses can produce 8000 silver coins per hour.


Price
Silver prices are normally quoted in . One troy ounce is equal to . The London silver fix is published every working day at noon London time. This price is determined by several major international banks and is used by London bullion market members for trading that day. Prices are most commonly shown as the United States dollar (USD), the (GBP), and the (EUR).


Applications

Jewellery and silverware
The major use of silver besides coinage throughout most of history was in the manufacture of and other general-use items, and this continues to be a major use today. Examples include for cutlery, for which silver is highly suited due to its antibacterial properties. Western concert flutes are usually plated with or made out of ;Brumby et al., pp. 65–67 in fact, most silverware is only silver-plated rather than made out of pure silver; the silver is normally put in place by . Silver-plated glass (as opposed to metal) is used for mirrors, , and Christmas tree decorations.

Because pure silver is very soft, most silver used for these purposes is alloyed with copper, with finenesses of 925/1000, 835/1000, and 800/1000 being common. One drawback is the easy tarnishing of silver in the presence of and its derivatives. Including precious metals such as palladium, platinum, and gold gives resistance to tarnishing but is quite costly; like , , , and do not totally prevent corrosion and tend to affect the lustre and colour of the alloy. Electrolytically refined pure silver plating is effective at increasing resistance to tarnishing. The usual solutions for restoring the lustre of tarnished silver are dipping baths that reduce the silver sulfide surface to metallic silver, and cleaning off the layer of tarnish with a paste; the latter approach also has the welcome side effect of polishing the silver concurrently.


Medicine
In medicine, silver is incorporated into wound dressings and used as an antibiotic coating in medical devices. Wound dressings containing silver sulfadiazine or silver nanomaterials are used to treat external infections. Silver is also used in some medical applications, such as (where tentative evidence indicates it reduces catheter-related urinary tract infections) and in endotracheal breathing tubes (where evidence suggests it reduces ventilator-associated ). The silver is bioactive and in sufficient readily kills . Silver ions interfere with enzymes in the bacteria that transport nutrients, form structures, and synthesise cell walls; these ions also bond with the bacteria's genetic material. Silver and silver nanoparticles are used as an antimicrobial in a variety of industrial, healthcare, and domestic application: for example, infusing clothing with nanosilver particles thus allows them to stay odourless for longer. Bacteria can, however, develop resistance to the antimicrobial action of silver. Silver compounds are taken up by the body like mercury compounds, but lack the toxicity of the latter. Silver and its alloys are used in cranial surgery to replace bone, and silver–tin–mercury amalgams are used in dentistry.Brumby et al. pp. 67–71 Silver diammine fluoride, the fluoride salt of a coordination complex with the formula Ag(NH3)2F, is a topical (drug) used to treat and prevent (cavities) and relieve dentinal hypersensitivity.


Electronics
Silver is very important in electronics for conductors and electrodes on account of its high electrical conductivity even when tarnished. Bulk silver and silver foils were used to make vacuum tubes, and continue to be used today in the manufacture of semiconductor devices, circuits, and their components. For example, silver is used in high quality connectors for , VHF, and higher frequencies, particularly in tuned circuits such as cavity filters where conductors cannot be scaled by more than 6%. Printed circuits and antennas are made with silver paints,
(2024). 9780780388833
Powdered silver and its alloys are used in paste preparations for conductor layers and electrodes, ceramic capacitors, and other ceramic components.Brumby et al., pp. 71–78


Brazing alloys
Silver-containing alloys are used for brazing metallic materials, mostly , , and copper-based alloys, tool steels, and precious metals. The basic components are silver and copper, with other elements selected according to the specific application desired: examples include zinc, tin, cadmium, palladium, , and . Silver provides increased workability and corrosion resistance during usage.Brumby et al., pp. 78–81


Chemical equipment
Silver is useful in the manufacture of chemical equipment on account of its low chemical reactivity, high thermal conductivity, and being easily workable. Silver (alloyed with 0.15% nickel to avoid recrystallisation of the metal at red heat) are used for carrying out alkaline fusion. Copper and silver are also used when doing chemistry with . Equipment made to work at high temperatures is often silver-plated. Silver and its alloys with gold are used as wire or ring seals for oxygen compressors and vacuum equipment.Brumby et al., pp. 81–82


Catalysis
Silver metal is a good catalyst for reactions; in fact it is somewhat too good for most purposes, as finely divided silver tends to result in complete oxidation of organic substances to and water, and hence coarser-grained silver tends to be used instead. For instance, 15% silver supported on α-Al2O3 or silicates is a catalyst for the oxidation of to at 230–270 °C. Dehydrogenation of to is conducted at 600–720 °C over silver gauze or crystals as the catalyst, as is dehydrogenation of to . In the gas phase, yields and yields , while organic are dehydrated to .


Photography
Before the advent of digital photography, which is now dominant, the photosensitivity of silver halides was exploited for use in traditional film photography. The photosensitive emulsion used in black-and-white photography is a suspension of silver halide crystals in , possibly mixed in with some noble metal compounds for improved photosensitivity, developing, and .

Colour photography requires the addition of special dye components and sensitisers, so that the initial black-and-white silver image couples with a different dye component. The original silver images are bleached off and the silver is then recovered and recycled. Silver nitrate is the starting material in all cases.Brumby et al., p. 82

The market for silver nitrate and silver halides for photography has rapidly declined with the rise of digital cameras. From the peak global demand for photographic silver in 1999 (267,000,000 or 8,304.6 ) the market contracted almost 70% by 2013.


Nanoparticles
Nanosilver particles, between 10 and 100 nanometres in size, are used in many applications. They are used in conductive inks for printed electronics, and have a much lower melting point than larger silver particles of micrometre size. They are also used medicinally in antibacterials and antifungals in much the same way as larger silver particles. In addition, according to the European Union Observatory for Nanomaterials (EUON), silver nanoparticles are used both in pigments, as well as cosmetics.


Miscellanea
Pure silver metal is used as a food colouring. It has the designation and is approved in the . Traditional Indian and Pakistani dishes sometimes include decorative silver foil known as , and in various other cultures, silver dragée are used to decorate cakes, cookies, and other dessert items.

Photochromic lenses include silver halides, so that ultraviolet light in natural daylight liberates metallic silver, darkening the lenses. The silver halides are reformed in lower light intensities. Colourless silver chloride films are used in radiation detectors. sieves incorporating Ag+ ions are used to seawater during rescues, using silver ions to precipitate chloride as silver chloride. Silver is also used for its antibacterial properties for water sanitisation, but the application of this is limited by limits on silver consumption. is similarly used to disinfect closed swimming pools; while it has the advantage of not giving off a smell like treatments do, colloidal silver is not effective enough for more contaminated open swimming pools. Small crystals are used in to cause rain.Brumby et al., pp. 83–84

The Texas Legislature designated silver the official precious metal of Texas in 2007.

(2024). 9781625110664, Texas State Historical Association.


Precautions
Silver compounds have low toxicity compared to those of most other , as they are poorly absorbed by the human body when ingested, and that which does get absorbed is rapidly converted to insoluble silver compounds or complexed by . However, silver fluoride and silver nitrate are caustic and can cause tissue damage, resulting in , , falling , cramps, paralysis, and respiratory arrest. Animals repeatedly dosed with silver salts have been observed to experience , slowed growth, of the liver, and fatty degeneration of the liver and kidneys; rats implanted with silver foil or injected with have been observed to develop localised tumours. Parenterally admistered colloidal silver causes acute silver poisoning.Brumby et al., pp. 88–91 Some waterborne species are particularly sensitive to silver salts and those of the other precious metals; in most situations, however, silver does not pose serious environmental hazards.

In large doses, silver and compounds containing it can be absorbed into the circulatory system and become deposited in various body tissues, leading to , which results in a blue-grayish pigmentation of the skin, eyes, and . Argyria is rare, and so far as is known, does not otherwise harm a person's health, though it is disfiguring and usually permanent. Mild forms of argyria are sometimes mistaken for , a blue tint on skin, caused by lack of oxygen.

Metallic silver, like copper, is an antibacterial agent, which was known to the ancients and first scientifically investigated and named the oligodynamic effect by Carl Nägeli. Silver ions damage the metabolism of bacteria even at such low concentrations as 0.01–0.1 milligrams per litre; metallic silver has a similar effect due to the formation of silver oxide. This effect is lost in the presence of due to the extreme insolubility of silver sulfide.

Some silver compounds are very explosive, such as the nitrogen compounds silver azide, silver , and silver fulminate, as well as , , and silver(II) oxide. They can explode on heating, force, drying, illumination, or sometimes spontaneously. To avoid the formation of such compounds, ammonia and should be kept away from silver equipment. Salts of silver with strongly oxidising acids such as and silver nitrate can explode on contact with materials that can be readily oxidised, such as organic compounds, sulfur and soot.


See also


Cited sources
  • (1968). 9780766138728, Journal of Chemical Education.


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