Discovery Information
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Who: Louis Vauquelin |
When: 1797 |
Where: France |
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Name Origin
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Greek: chroma (colour). Due to the many colourful compounds that can be made from it. |
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Sources
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Does not occur free in nature. Chromite [Fe,Mg(CrO4)] is its most important mineral. Chromium ores are mined today in South Africa, Zimbabwe, Finland, India, Kazakihstan and
the Philippines. Reserves are estimated at over 1 billion tonnes.
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Uses
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Used to make stainless steel. Also used in plating for car parts, magnetic tape, tools, knives, camouflage paint, stereos,
and lasers. It gives rubies and emeralds their colour.
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Chromium(VI) oxide (CrO3) is used to manufacture magnetic tape, where its higher coercivity than iron oxide tapes gives better performance.
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Notes
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Chromium metal and chromium(III) compounds are not usually considered health hazards, but hexavalent chromium (chromium VI)
compounds can be toxic if orally ingested or inhaled. The lethal dose of poisonous chromium (VI) compounds is about one half
teaspoon of material. Most chromium (VI) compounds are irritating to eyes, skin and mucous membranes. Chronic exposure to
chromium (VI) compounds can cause permanent eye injury, unless properly treated. Chromium(VI) is an established human carcinogen.
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World Health Organization recommended maximum allowable concentration in drinking water for chromium (VI) is 0.05 milligrams
per liter.
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