History: Chromium was discovered in 1797 by French chemist Nicolas Vanquelin. In work conducted to

Chromium rachida dati (Cr) is a metallic chemical element of group VI the secondary, with atomic number 24, atomic weight 51.996, the outer electronic shell structure rachida dati 3d54s, valence II, III, IV, V, VI. It is the first element of group VI-a. Gray-white metal, shiny, denitatea rachida dati 7.2 [kg / dm 3], the melting point it 890 C, boiling point 2480 C. Pure is malleable, ductile and tenacious.
Its name comes from the Greek word chroma, meaning color, because the majority rachida dati of its compounds are intensely colored. Chromium oxide was used for the first time in 2000 years ago, during the Qin dinsatiei by China to cover the tops of arms. Chromium in combination with other elements has varied coloring, which is used as a pigment in paints and varnishes.
History: Chromium was discovered in 1797 by French chemist Nicolas Vanquelin. In work conducted to determine chromium Vanquelin rachida dati used samples from a mineral called chromium and lead which was in reality Croco and lead chromate (CrO4Pb). This mineral, reddish color, was identified in 1762, in Siberia. It got its name from the Greek word Croco Croc, which means cinnamon (based on color similarity). Analyzing crocoitul, Vanquelin got a heavy precipitate of lead and a yellow solution of chromic acid. Chromic acid by heating coal, Vanquelin won first amounts of chromium.
Subsequently, the French physicist AE Becquerel, in 1843, manages to get chrome metal electrolytically, and in 1898, Goldschmit obtains aluminothermic method. Chromium is a metal quite widespread in the earth's crust, but only in the form of chemical combinations, Clark or having a value of 0.033%.
This entry WAS posted in Chrome, Transition metals and tagged general characteristics of chromium, chromium (Cr), about chromium chemical element chromium on 05/09/2014 by Iasmy. Post navigation Item Test Lead Manganese, general and historian
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