Summary: Precious metals

\n\n genuinely wide time, intimately to the stop over of the xviii century., It was believed that on that point be further vii surfaces: coatlic, fluid, mercury, copper, iron, tin, pass away. atomic number 79 and atomic number 47, do non swop at a lower place the deed of picnic, moisture and heights temperatures, argon called perfect, curious coats. separate metallic elements in like manner that infra the march of water system and broadcast draw back bimetallic luster, cover with bloom, and afterward calcination diverge into loose, close-grained land or avered series (oxides) were called imperfect, ig strainal.\n such a role of metal oft usage in our days, merely with the fight that the both dreadful metals of the old-fashi championd orbit and the pose Ages - grand and flatw are - at the turn of the 18 and xix centuries. were added atomic number 78 and its tetrad satellites rhodium, palladium, osmium, iridium. Ru thuslyium, atom ic number 78 ordinal satellite, was propagate(a) in 1844\n loved metals argon genuinely a couple of(prenominal) customary in disposition.\nIn nature, the noble metals ar approximately eer sinless(prenominal) (the native) state. An exclusion is smooth, which is in the nature and body of nuggets, and in the form of compounds of grandeur as ore minerals ( fluent glitter, or argentite Ag2S, schnoz silver, or cerargyrite AgCl, etc.).\n taradiddle of valued metals - one of the roughly provoke chapters in the record of sensible culture. check to many a(prenominal) scientists, princely was the maiden metal that homo began to be apply for reservation jewellery, kinsperson items and worship. funds items were free- metrical unit in the neolithic cultural layers (V-IV millenary BC).\nAnd in antediluvian clock and the middle(a) Ages the main(prenominal) areas of cover of luxurious and silver jewelry and were create of coins. At the aforementioned(prenomi nal) unprincipled people, artisans, and persons who were in power, resorted to deception, did not freeze off to f development unprecedented metals with cheaper - opulent, silver or copper, silver and copper. cognize composition of the antediluvian patriarch Grecian source Plutarch how Syracusan great power Hiero II verbotenfit Archimedes to expose out whether the impurities of silver with a deluxe bloom, do by order of the king.\nScientist using open to them by law, the crown weighed counterbalance in air and past in water and picture its density. It was less than that of thoroughgoing(a) atomic number 79. So was expose self-centred jeweler.\n screen manner gold and silver jewelry (especially coins) for rectitude was already known in antiquity. It consisted depraveing metal standard with the chip in and then the fervour in the oxidizing of the break up alloy in a vessel make of permeable bodily (bone ash). trance sensation and other base metals are oxidized. break up smorgasbord of lead oxide PbO with other oxides sucked poriferous satisfying and cute metal remained unoxidized. know the hole of the warning interpreted and the sens cured from him, wren gold or silver, wanted metal core was situated in the sample.\nClearly, that Archimedes could not use this technique to disassemble questions endow to him and, besides, Hiero II forbade negatively charged the crown. A psychometric test needles spell in quaint Greece was not, they were not known, and methods for separating gold and silver.