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Naturally occurring chromium is composed of four stable isotopes; 50 Cr, 52 Cr, 53 Cr and 54 Cr, with 52 Cr being the most abundant (83.789% natural abundance). 50 Cr is observationally stable , as it is theoretically capable of decaying to 50 Ti via double electron capture with a half-life of no less than 1.3 × 10 18 years.
Hexavalent chromium (chromium(VI), Cr(VI), chromium 6) is any chemical compound that contains the element chromium in the +6 oxidation state (thus hexavalent). [1] It has been identified as carcinogenic, which is of concern since approximately 136,000 tonnes (150,000 tons) of hexavalent chromium were produced in 1985. [ 2 ]
Chromium compounds are compounds containing the element chromium (Cr). Chromium is a member of group 6 of the transition metals . The +3 and +6 states occur most commonly within chromium compounds, followed by +2; charges of +1, +4 and +5 for chromium are rare, but do nevertheless occasionally exist.
Heating a solution of Cr(CO) 6 in an aromatic solvent results in replacement of three CO ligands. The reactions are especially favorable for electron-rich arenes: Cr(CO) 6 + C 6 H 5 R → Cr(CO) 3 (C 6 H 5 R) + 3 CO. The products are "piano stool complexes". These species are typically yellow solids. One example is (benzene)chromium tricarbonyl.
Fuchsite, also known as chrome mica, is a chromium (Cr)-rich variety of the mineral muscovite, belonging to the mica group of phyllosilicate minerals, with the chemical formula K(Al,Cr) 2 (AlSi 3 O 10)(OH) 2. [2] Trivalent chromium replaces one of the aluminium (Al) atoms in the general muscovite formula producing the apple green hue ...
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Cr(III) is an essential nutrient, required for lipid and glucose metabolism in animals and humans. In contrast, the second most stable form, hexavalent chromium (Cr(VI)), is generally produced through human activity and rarely seen in nature (as in crocoite), and is a highly toxic carcinogen that may kill animals and humans if ingested in large ...
Hexavalent chromium plating, also known as hex-chrome, Cr 6+, and chrome(VI) plating, uses chromium trioxide (CrO 3, also known as chromic anhydride) as the main ingredient. Hexavalent chromium plating solution is used for both decorative and hard plating, as well as bright dipping of copper alloys, chromic acid anodizing , and chromate ...