Silver compounds include silver chloride (AgCl), silver bromide (AgBr), and silver iodide (AgI). Parenterally admistered colloidal silver causes acute silver poisoning. , The word "silver" appears in Old English in various spellings, such as seolfor and siolfor.  Silver also has the lowest contact resistance of any metal. 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. 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). Risch/E. Silver, chemical element of atomic number 47, a white lustrous metal valued for its decorative beauty and electrical conductivity. , The C–Ag bond is stabilized by perfluoroalkyl ligands, for example in AgCF(CF3)2. , The common oxidation states of silver are (in order of commonness): +1 (the most stable state; for example, silver nitrate, AgNO3); +2 (highly oxidising; for example, silver(II) fluoride, AgF2); and even very rarely +3 (extreme oxidising; for example, potassium tetrafluoroargentate(III), KAgF4).  The stability of the Roman currency relied to a high degree on the supply of silver bullion, mostly from Spain, which Roman miners produced on a scale unparalleled before the discovery of the New World.
(For treatment of silver’s use in ornamental and household objects, see metalwork.). Argyria is rare, and so far as is known, does not otherwise harm a person's health, though it is disfiguring and usually permanent. Crawford, Michael H. (1974). 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)2]3−; and cyanide extraction for silver (and gold) works by the formation of the complex [Ag(CN)2]−. This observation explains the low hardness and high ductility of single crystals of silver. Silver is also used in some medical applications, such as urinary catheters (where tentative evidence indicates it reduces catheter-related urinary tract infections) and in endotracheal breathing tubes (where evidence suggests it reduces ventilator-associated pneumonia). , Nanosilver particles, between 10 and 100 nanometres in size, are used in many applications.  The Romans also recorded the extraction of silver in central and northern Europe in the same time period. It is also employed to convert alkyl bromides into alcohols. Silver has numerous nuclear isomers, the most stable being 108mAg (t1/2 = 418 years), 110mAg (t1/2 = 249.79 days) and 106mAg (t1/2 = 8.28 days).  Furthermore, silver's Pauling electronegativity of 1.93 is higher than that of lead (1.87), and its electron affinity of 125.6 kJ/mol is much higher than that of hydrogen (72.8 kJ/mol) and not much less than that of oxygen (141.0 kJ/mol). W3C Color Name: Silver RGB: 192, 192, 192 - HSL: 0.00, 0.00, 0.75 Web Safe Color: No All three halides are derived from silver nitrate (AgNO3), which is the most important of the inorganic silver salts.  The +1 state is by far the most common, followed by the easily reducible +2 state.
, Commercial-grade fine silver is at least 99.9% pure, and purities greater than 99.999% are available. Most silver is produced as a byproduct of copper, gold, lead, and zinc refining. , Silver is useful in the manufacture of chemical equipment on account of its low chemical reactivity, high thermal conductivity, and being easily workable. This almost equal abundance is rare in the periodic table. Its reactivity is intermediate between that of copper (which forms copper(I) oxide when heated in air to red heat) and gold.
Image Credit: scyther5/iStock/Getty Images If you like to explore and stay on top of the latest color trends, look to the Pantone company -- recognized worldwide as the authority on color. Silver dissolves readily in nitric acid and in hot concentrated sulfuric acid. Equipment made to work at high temperatures is often silver-plated. , Photochromic lenses include silver halides, so that ultraviolet light in natural daylight liberates metallic silver, darkening the lenses. 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.  Pure silver has the highest thermal conductivity of any metal, although the conductivity of carbon (in the diamond allotrope) and superfluid helium-4 are even higher. Many non-stoichiometric selenides and tellurides are known; in particular, AgTe~3 is a low-temperature superconductor. , Silver metal is attacked by strong oxidizers such as potassium permanganate (KMnO4) and potassium dichromate (K2Cr2O7), and in the presence of potassium bromide (KBr). Besides these other salts, silver nitrate is also the starting material for the production of the silver cyanide used in silver plating.  Silver compounds are taken up by the body like mercury compounds, but lack the toxicity of the latter. *Alina Gondareva, Blue Color Palettes, color selection, contrasting color, dark emerald green, dark green, dark jade color, emerald green, jade color, monochrome color palette, pastel shades and contrasting color, shades of green, silver blue, turquoise.
 Both isotopes of silver are produced in stars via the s-process (slow neutron capture), as well as in supernovas via the r-process (rapid neutron capture). A strong yet thermally stable and therefore safe fluorinating agent, silver(II) fluoride is often used to synthesize hydrofluorocarbons. As one historian put it, silver "went round the world and made the world go round. Silver / #c0c0c0 hex color code information, schemes, description and conversion in RGB, HSL, HSV, CMYK, etc. , Silver is an extremely soft, ductile and malleable transition metal, though it is slightly less malleable than gold. By the end of the dynasty, silver coins produced in Mexico, introduced by Spanish sailors based in the Philippines, were becoming common on the south coast.…. From the peak global demand for photographic silver in 1999 (267,000,000 troy ounces or 8304.6 metric tonnes) the market contracted almost 70% by 2013. Mitteldeutscher Archäologentag vom 17. bis 19. Radiogenic 107Ag was first discovered in the Santa Clara meteorite in 1978. Hence, Ag+ is the stable species in aqueous solution and solids, with Ag2+ being much less stable as it oxidizes water. Silver’s physical and chemical properties are intermediate between those of copper and gold. It is cognate with Old High German silabar; Gothic silubr; or Old Norse silfr, all ultimately deriving from Proto-Germanic *silubra. Silver cyanide solutions are used in electroplating of silver. 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. , Naturally occurring silver is composed of two stable isotopes, 107Ag and 109Ag, with 107Ag being slightly more abundant (51.839% natural abundance). , Silver-containing brazing alloys are used for brazing metallic materials, mostly cobalt, nickel, and copper-based alloys, tool steels, and precious metals. "Silver, Silver Compounds, and Silver Alloys" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2008. , Pure silver metal is used as a food colouring.
2008. Announcing our NEW encyclopedia for Kids! , Silver metal is a good catalyst for oxidation 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 carbon dioxide and water, and hence coarser-grained silver tends to be used instead. , 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.
 The electrical conductivity of silver is the greatest of all metals, greater even than copper, but it is not widely used for this property because of the higher cost.