Chromium is a bright, blue/white metal with excellent corrosion resistance. It is obtained by the aluminium reduction of Cr2O3, the source of which is chromite, a double oxide of chromium and iron which generally also contains magnesium. Chromium is soluble in HCl and H2SO4, but not in H3PO4, HNO3 or HClO4 due to the formation of a stable and insoluble oxide layer on its surface; this, along with its hardness, has been used to advantage in the chromium plating of steel which has good corrosion resistance. Chromium is alloyed with nickel in the manufacture of heat resisting alloys, and with iron, or nickel and iron, to produce stainless and heat resistant steels. Chromium is an important trace element for humans as it assists in the manufacture of glucose.
- 1780 by N.L. Vanquelin in Paris, France.
- 100 ppm in the earth's crust.
|Atomic / Molecular Weight||51.996||gmol-1||Clip|
|Specific heat capacity||448||Jkg-1K-1||Clip|
|Latent heat of fusion||134000||Jkg-1||Clip|
|Acoustic wave velocity (longitudinal bulk waves)||6608||ms-1||Clip|
|Acoustic wave velocity (Irrotational waves)||6229||ms-1||Clip|
|Acoustic wave velocity (Shear waves)||4005||ms-1||Clip|
|Acoustic wave velocity (Rayleigh waves)||3655||ms-1||Clip|
|Bulk Modulus of Rigidity||160100000000||Nm-2||Clip|