News tagged with chromium
Using graphene, scientists develop a less toxic way to rust-proof steel
(Phys.org) -- University at Buffalo researchers are making significant progress on rust-proofing steel using a graphene-based composite that could serve as a nontoxic alternative to coatings that contain hexavalent ...
Nanotechnology / Nanomaterials
May 18, 2012 |
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MSU chemists become the first to solve an 84-year-old theory
The same principle that causes figure skaters to spin faster as they draw their arms into their bodies has now been used by Michigan State University researchers to understand how molecules move energy around following the ...
Dec 22, 2011 |
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New evidence found for the oldest oxygen-breathing life on land
New University of Alberta research shows the first evidence that oxygen-breathing bacteria occupied and thrived on land 100 million years earlier than previously thought.
Space & Earth / Earth Sciences
Oct 19, 2011 |
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Helping materials handle extreme stress
Important pressurized water nuclear reactor components are being made from a nickel-base alloy that contains twice the amount of chromium as the material previously used. The new alloy, called alloy 690, performs ...
Nanotechnology / Nanomaterials
Oct 11, 2011 |
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Second chemical leak at Australian plant
An Australian chemical company admitted Saturday that one of its sites had leaked toxic compounds for the second time in two weeks.
Aug 21, 2011 |
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Ions control shape of nanofibers grown on clear substrate
Researchers from North Carolina State University have found a new way to develop straight carbon nanofibers on a transparent substrate. Growing such nanofiber coatings is important for use in novel biomedical ...
Nanotechnology / Nanomaterials
Aug 16, 2011 |
5 / 5 (3) |
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Toxic chromium found in Chicago's drinking water
Chicago's first round of testing for a toxic metal called hexavalent chromium found that levels in local drinking water are more than 11 times higher than a health standard California adopted last month.
Aug 08, 2011 |
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State sets goal for limiting drinking water pollutant
The California Environmental Protection Agency has issued the nation's first public health goal for hexavalent chromium, the cancer-causing heavy metal made infamous after activist Erin Brockovich sued in 1993 over contaminated ...
Jul 30, 2011 |
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Nearly one in ten toys in China unsafe: watchdog
China's safety watchdog has found nearly one in ten toys in the domestic market is unsafe, highlighting widespread quality problems in the country's poorly regulated manufacturing industry.
May 31, 2011 |
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Missing chromium is clue to planet formation
Early in the formation of the Earth, some forms of the element chromium separated and disappeared deep into the planet's core, a new study by UC Davis geologists shows.
Space & Earth / Earth Sciences
Feb 24, 2011 |
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The Spin Doctor
An electron spin can be compared to the needle of a compass that points either north or south. Some electrons in a full shell point up, canceling out the electromagnetic fields of an equal number of electrons ...
Jan 13, 2011 |
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US orders more testing of chromium-6 in tap water
The Environmental Protection Agency has asked local US communities to test more carefully for hexavalent chromium, a probable carcinogen.
Jan 13, 2011 |
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High water uptake capacity of mesoporous material ideal for use in heat transformation applications
The search for sustainable ways of producing energy is currently a very popular and important topic of investigation. Water adsorption/desorption is a process that can be used for the transformation of energy. ...
Jan 03, 2011 |
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Removal of hexavalent chromium from your drinking water
The only way to learn if your water source has hexavalent chromium is to check with your public water supplier and request a water quality report, said NJIT Professor Taha Marhaba, a civil/environmental engineer. Most municipal ...
Dec 22, 2010 |
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US water has large amounts of likely carcinogen: study
A US environmental group has found that drinking water in 35 American cities contains hexavalent chromium, a probable carcinogen, The Washington Post reported Sunday.
Dec 19, 2010 |
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Chromium
Chromium ( /ˈkroʊmiəm/ kroh-mee-əm) is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable. The name of the element is derived from the Greek word "chrōma" (χρώμα), meaning colour, because many of its compounds are intensely coloured. Chromium oxide was used by the Chinese in the Qin dynasty over 2,000 years ago to coat weapons such as bronze crossbow bolts and steel swords found at the Terracotta Army. It later came to the attention of the west when it was discovered by Louis Nicolas Vauquelin in the mineral crocoite (lead(II) chromate) in 1797. Crocoite was used as a pigment, and after the discovery that the mineral chromite also contains chromium, this latter mineral was used to produce pigments as well.
Chromium was regarded with great interest because of its high corrosion resistance and hardness. A major development was the discovery that steel could be made highly resistant to corrosion and discoloration by adding chromium to form stainless steel. This application, along with chrome plating (electroplating with chromium) are currently the highest-volume uses of the metal. Chromium and ferrochromium are produced from the single commercially viable ore, chromite, by silicothermic or aluminothermic reaction or by roasting and leaching processes.
Although trivalent chromium (Cr(III)) is required in trace amounts for sugar and lipid metabolism, few cases have been reported where its complete removal from the diet has caused chromium deficiency. In larger amounts and different forms chromium can be toxic and carcinogenic. The most prominent example of toxic chromium is hexavalent chromium (Cr(VI)). Abandoned chromium production sites often require environmental cleanup.
For more information about Chromium, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
