An Oregon State University researcher who made color history in 2009 with a vivid blue pigment has developed durable, reddish magentas inspired by lunar mineralogy and ancient Egyptian chemistry.
Analytical Chemistry
Apr 16, 2024
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14
Nano zero-valent iron (nZVI) is often used to remove chromium (VI), a heavy metal contaminant, because of its large specific surface area and high reducing activity. However, its effectiveness in removing trace heavy metals ...
Analytical Chemistry
Mar 4, 2024
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1
Wildfires can transform a benign metal in soils and plants into toxic particles that easily become airborne, according to a new study from Stanford University.
Earth Sciences
Dec 12, 2023
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41
A large international team of space scientists, geochemists, and engineers, has found that water that existed on the parent of Ryugu had an impact on the distribution of elements on the asteroid. In their paper published ...
Chromium hydride (CrH), a molecule that's relatively rare and particularly sensitive to temperature, is useful as a "thermometer for stars," according to astronomer Laura Flagg, because it's abundant only in a narrow range ...
Astronomy
Aug 28, 2023
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109
Expensive noble metals often play a vital role in illuminating screens or converting solar energy into fuels. Now, chemists at the University of Basel have succeeded in replacing these rare elements with a significantly cheaper ...
Analytical Chemistry
Aug 14, 2023
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65
Researchers find calcium outshines chromium in the catalytic production of ammonia. Working together, a humble trio of calcium atoms have defied expectations to break apart one of the strongest chemical bonds known. The atoms ...
Materials Science
Aug 10, 2023
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14
The origin of Mercury, the closest planet to the sun, is mysterious in many ways. It has a metallic core, like Earth, but its core makes up a much larger fraction of its volume—85% compared to 15% for Earth.
Planetary Sciences
Jul 10, 2023
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250
Hydrogen produced from renewable energy sources can be used as fuels that do not contribute to CO2 emissions, and therefore is emerging as an important future power source.
Analytical Chemistry
Apr 17, 2023
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77
Toxic heavy metals found in wastewater have health and safety ramifications for communities affected by pollution. Hexavalent chromium is a dangerous, cancer-causing byproduct of industrial processes that is known to cause ...
Analytical Chemistry
Mar 30, 2023
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12
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.
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