![]() The electron configuration of Cr violates the Aufbau principle by the recording of 3d orbital to form a new electronic configuration to gain extra chemical stability by exchanging energy.Chromium is the fourth transition metal after scandium, titanium, and vanadium in the periodic table with electron configuration 3d 5 4s 1.The pure form of the element may be obtained by reducing Cr (III) chloride with metallic calcium in the melting solution of CaCl 2 or BaCl 2.Metallic chromium is obtained by the reduction of Cr 2O 3 by aluminum powdered through the Thermite process.The produced dichromate is reduced to Cr 2O 3 by heating with carbon.The sodium chromite is leached out with water and converted to sodium dichromate by adding concentrated sulfuric acid.Metallic chromium is oxidized to form sodium chromite and iron is converted to F 2O 3.Powdered chromite is heated (1000 ☌ to 1300 ☌) with sodium carbonate and quicklime in a revelatory furnace in presence of excess air.Greyish white shiny metal, chromium is extracted from chromite (Cr 2O 3). It has also nineteen radioactive isotopes produced from different types of radioactive decay or nuclear reaction. Naturally the chemical element, chromium contains four stable isotopes like 52Cr (83.76 percent), 53Cr (9.55 percent), 50Cr (4.31 percent), and 54Cr (2.38 percent). The presence of Cr +3 and Cr +4 ions in the earth’s environment strongly depend on the pH scale and oxidative properties of the soil of location. In gemstones, some chromium ion (Cr +3) ions are substituted by aluminum (Al +3) ions. Chromium occurs mainly as chromite (FeCr 2O 4), found in South Africa, India, Philippines, Turkey, and Russian countries.Ĭrocoite (PbCrO 4) and chrome ochre (Cr 2O 3) are the other minerals of the metal found in the earth’s environment. It is the 21st most abundant chemical element in the earth’s crust (0.04 percent by weight). Chromium is a transition metal that lies between vanadium and manganese. ![]() It is placed in group 6 and period 4 of the periodic table. The oxidation state vs free energy diagram shows that the stable oxidation number or state of chromium is +3. It suggests less participation of d- electron in metallic chemical bonding. The melting point and density of chromium are higher than those of vanadium. Properties of chromiumīody-centered cubic crystal lattice, chromium has a valence shell electronic configuration 3d 5 4s 1. Chromates produce deep blue colour with hydrogen peroxide in acid solution. It is readily detected by the borax bead test (green) and the yellow melt of chromates is formed on fusion with alkali or an oxidizing agent. In1797, chromium was discovered by French chemist Nicolas-Louis Vauquelin from Siberian mineral-like PbCrO 4, and the name of the element was derived from the Greek latter chroma means colour.
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