Chromium
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| General Properties | |
|---|---|
| Atomic number | 24 |
| Atomic mass | 51.996amu |
| Atomic radius | 166pm |
| Electron Configuration | [Ar] 3d5 4s1 |
| Density | 7.140g/cm3 |
| Melting point | 1907°C |
| Boiling point | 2671°C |
| First discovered/ developed | 1794 |
| Most common compound on Earth | FeCr2VO4 (Chromite Ore) |
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Description and uses
Chromium is the 24th element of the periodic table. In 1761, Johann Gottlob Lehmann discovered “Siberian red lead” in a mine. What he had actually found was what
is known now as crocoite (PbCrO4). Louis Nicolas Vauquelin was given a sample of this ore in 1794, where he produced chromium trioxide
(CrO3) by mixing it with hydrochloric acid (HCl). He then extracted the chromium trichloride by heating it in a furnace with charcoal. He later
discovered traces of chromium in emeralds and rubies, which we now know is what give them their distinctive colours (along with vanadium
in emeralds)
Chromium and vanadium are actually quite similar in uses. Like vanadium, chromium is also used in steel, more specifically stainless steel. It helps the steel's
corrosion resistance, as well as its general hardness. It is used in household products such as cutlery all the way to industrial tools.
Chromium has 4 naturally occurring isotopes, with atomic weights ranging from 50 to 54. 52Cr is the most abundant isotope, taking up around 84% of
all chromium atoms. It is followed by 53Cr, which takes up around 10%.