S P O I L M E S I L L Y . C O M . A U All About Silver { T H E B E S T W A Y S T O C L E A N S I L V E R } SPOILMESILLY.COM.AU SILVER AND HOW TO CLEAN SILVER IN MANY WAYS Silver Silver is a chemical element with symbol Ag (from the Latin argentum, derived from the Proto-Indo- European h₂erǵ: "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earth's crust in the pure, free elemental form ("native silver"), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Jewellery and silverware The major use of silver besides coinage HISTORY OF throughout most of history was in the manufacture of jewellery and other general-use SILVER items, and this continues to be a major use today. Examples include table silver for cutlery, for which silver is highly suited due to its antibacterial properties. Silver was one of the seven metals of antiquity that were known to prehistoric humans and whose discovery is thus lost to history . In particular, the three metals of group 11, copper, silver, and gold, occur in the elemental form in nature and were probably used as the first primitive forms of money as opposed to simple bartering. However, unlike copper, silver did not lead to the growth of Conservation & metallurgy on account of its low structural strength, and was more Restoration often used ornamentally or as money . The conservation and Since silver is more reactive than gold, supplies of native silver were restoration of silver objects is an activity much more limited than those of gold. For example, silver was more dedicated to the expensive than gold in Egypt until around the fifteenth century BC: preservation and protection of objects of the Egyptians are thought to have separated gold from silver by historical and personal U heating the metals with salt, and then reducing the silver chloride A value made from silver. produced to the metal. M O Quoted references can also be helpful. C . References to people can also be made Y The situation changed with the discovery of cupellation, a technique L through the written accounts of interviews L I and debates confirming the factuality of the that allowed silver metal to be extracted from its ores. While slag S writer’s information and his reliability. The heaps found in Asia Minor and on the islands of the Aegean Sea E M writer can use redirection to ensure that L indicate that silver was being separated from lead as early as the 4th I the reader keeps reading the article and to O draw her attention to other articles millennium BC, and one of the earliest silver extraction centres in P Europe was Sardinia in early the Chalcolithic period, these techniques S did not spread widely until later, when it spread throughout the region and beyond. Its compounds are used in photographic and SILVER Xray film. Dilute solutions of silver nitrate and other silver compounds are used as disinfectants and microbiocides (oligodynamic effect), added to bandages and wound-dressings, catheters, and other medical instruments. Silver is a chemical element with symbol Ag Characteristics (from the Latin argentum, derived from the Proto-Indo-European h₂erǵ: "shiny" or Silver is similar in its physical and chemical "white") and atomic number 47. A soft, properties to its two vertical neighbours in white, lustrous transition metal, it exhibits group 11 of the periodic table, copper and the highest electrical conductivity, thermal gold. Its 47 electrons are arranged in the conductivity, and reflectivity of any metal. configuration [Kr]4d105s1, similarly to The metal is found in the Earth's crust in the pure, free elemental form ("native silver"), copper ([Ar]3d104s1) and gold as an alloy with gold and other metals, and ([Xe]4f145d106s1); group 11 is one of the in minerals such as argentite and few groups in the dblock which has a chlorargyrite. Most silver is produced as a completely consistent set of electron byproduct of copper, gold, lead, and zinc configurations. This distinctive electron refining. configuration, with a single electron in the Silver has long been valued as a precious highest occupied s subshell over a filled d metal. Silver metal is used in many bullion subshell, accounts for many of the singular coins, sometimes alongside gold:[4] while it properties of metallic silver . is more abundant than gold, it is much less abundant as a native metal.[5] Its purity is typically measured on a per-mille 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 S P human cultures. O I Other than in currency and as an investment L M medium (coins and bullion),[6] silver is used E S in solar panels, water filtration, jewellery, I L ornaments, high-value tableware and L Y utensils (hence the term silverware), in . C electrical contacts and conductors, in O specialized mirrors, window coatings, in M . A catalysis of chemical reactions, as a colorant U in stained glass and in specialised | P confectionery. A G E 3 The electrical conductivity of silver is the greatest of all metals, greater even than copper, but it is not widely used for this SILVER property because of the higher cost. An exception is in radio-frequency engineering , particularly at VHF and higher frequencies where silver plating improves electrical conductivity because those currents tend to flow on the surface of conductors rather than through the interior. During World Silver is an extremely soft, ductile and War II in the US, 13540 tons of silver were malleable transition metal, though it is used in electromagnets for enriching slightly less malleable than gold. Silver uranium, mainly because of the wartime crystallizes in a face-centered cubic lattice shortage of copper. Pure silver has the with bulk coordination number 12, where highest thermal conductivity of any metal, only the single 5s electron is delocalized, although the conductivity of carbon (in the similarly to copper and gold. Unlike metals diamond allotrope) and superfluid helium-4 with incomplete d-shells, metallic bonds in are even higher. Silver also has the lowest silver are lacking a covalent character and contact resistance of any metal. are relatively weak. This observation Silver readily forms alloys with copper and explains the low hardness and high ductility gold, as well as zinc. Zinc-silver alloys with of single crystals of silver. low zinc concentration may be considered Silver has a brilliant white metallic luster as face-centred cubic solid solutions of zinc that can take a high polish, and which is so in silver, as the structure of the silver is characteristic that the name of the metal largely unchanged while the electron itself has become a colour name. Unlike concentration rises as more zinc is added. copper and gold, the energy required to Increasing the electron concentration excite an electron from the filled d band to further leads to body-centred cubic the s-p conduction band in silver is large (electron concentration 1.5), complex cubic enough (around 385 kJ/mol) that it no (1.615), and hexagonal close-packed phases longer corresponds to absorption in the (1.75). visible region of the spectrum, but rather in the ultraviolet; hence silver is not a coloured S P metal. Protected silver has greater optical O I reflectivity than aluminium at all L M wavelengths longer than ~450 nm. At E S wavelengths shorter than 450 nm, silver's I L reflectivity is inferior to that of aluminium L Y and drops to zero near 310 nm. C Very high electrical and thermal O conductivity is common to the elements in M . A group 11, because their single s electron is U free and does not interact with the filled d | P subshell, as such interactions (which occur A in the preceding transition metals) lower G E electron mobility . 4 SILVER HISTORY Silver was one of the seven metals of antiquity that were known to prehistoric humans and whose discovery is thus lost to history . In particular, the three metals of group 11, copper, silver, and gold, occur in the elemental form in nature and were probably used as the first primitive forms of money as opposed to simple bartering. However, unlike copper, silver did not lead to the growth of metallurgy on account of its low structural strength, and was more often used ornamentally or as money . 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: the Egyptians are thought to have separated gold from silver by heating the metals with salt, and then reducing the silver chloride produced to the metal. The situation changed with the discovery of cupellation, a technique that allowed silver S P metal to be extracted from its ores. While O I slag heaps found in Asia Minor and on the L islands of the Aegean Sea indicate that M E silver was being separated from lead as S I L early as the 4th millennium BC, and one of L Y the earliest silver extraction centres in . C Europe was Sardinia in early the O Chalcolithic period, these techniques did M .