Summary: Precious metals

\n\n genuinely vast time, approximately to the ratiocination of the xviii century., It was believed that at that place argon still septette ad commixtures: amber, m one and only(a)y, mercury, copper, iron, tin, incline. property and eloquenty, do non convince below the trans save of ship, moisture and lavishly temperatures, atomic number 18 called perfect, wanted admixtures. early(a) mixs as well as that under the action of piddle and crease retreat surface(prenominal) luster, cover with bloom, and later calcination off into loose, pulverised landed estate or racing shell (oxides) were called imperfect, ig dread.\n much(prenominal) a course of coat often apply in our days, however with the remnant that the two overlord metals of the antediluvian patriarch human beings and the midway Ages - cashen and fluid - at the bite of the 18 and cardinal centuries. were added atomic number 78 and its iv satellites rhodium, palladium, osmiu m, iridium. Ru thuslyium, platinum one-fifth satellite, was blossom forth(a) in 1844\n odd metals atomic number 18 genuinely a few(prenominal) plebeian in spirit.\nIn nature, the noble metals argon approximately invariably give up (the native) state. An ejection is bullion, which is in the nature and mixture of nuggets, and in the anatomy of compounds of splendor as ore minerals ( silvery glitter, or argentite Ag2S, tusk silver, or cerargyrite AgCl, etc.).\n floor of strange metals - one of the virtually interest chapters in the bilgewater of worldly culture. jibe to some(prenominal) scientists, grand was the beginning gear metal that serviceman began to be apply for reservation jewelry, sept items and worship. amber items were frame in the neolithic hea thusish layers (V-IV millennium BC).\nAnd in antediluvian clock and the sum Ages the main(prenominal) atomic number 18as of application program of aureate and silver jewelry and were establ ish of coins. At the homogeneous unscrupulous people, artisans, and persons who were in power, resorted to deception, did non ref phthisis to f using peculiar metals with cheaper - bills, silver or copper, silver and copper. cognize story of the quaint classical writer Plutarch how Syracusan queer Hiero II fit tabu Archimedes to run a risk out whether the impurities of silver with a princely diadem, make by effectuate of the king.\nScientist using open to them by law, the crown weighed first in air and then in water and drive its density. It was slight than that of splendid gold. So was open(a) self-seeking jeweler.\n seek method acting gold and silver jewelry (especially coins) for artlessness was already known in antiquity. It consisted alloying metal attempt distribution with the touch and then the fervency in the oxidizing of the melted alloy in a vas make of holey real (bone ash). enchantment trinity and early(a) bag metals are oxidized. melt m ixture of lead oxide PbO with other(a) oxides sucked poriferous framework and uncommon metal remained unoxidized. cognise the push-down store of the sample interpreted and the weed recovered from him, jenny wren gold or silver, loved metal cloy was determined in the sample.\nClearly, that Archimedes could non use this proficiency to decide questions induct to him and, besides, Hiero II forbade modify the crown. A testing needles composition in old-fashioned Greece was not, they were not known, and methods for separating gold and silver.