Chromium :: essays research papers

ChromiumChromium is a very hard, brittle, gray metal, which is sometimesrefer departure to as Siberian red lead. It does not out of practice(p) easily and becomes shiny andbright when it is polished. The shiny trim on our automobile bumpers and doorhandles is usually electroplated chromium.Most chromium comes from something called chromite which is a mixtureof chromium , iron, and oxygen. Chromite is a common rather ordinary blackmineral that no one really noticed until more recent times. Nearly all theworlds supply of chromite comes from Zimbabwe, Russia, Turkey, south-central Africa,Cuba, and the Philippines. The United States imports almost all its chromite.Chromium is added to other metals to make them harder and moreresistant to chemicals. Small quantities mixed with stigma make the metalstainless. Stainless steel is used to make cutlery and kitchen equipmentbecause it does not rust easily and takes a mirror-like polish. This steelcontains about 13 per centum chromium and 0.3 percent carbon. The hardness of steelcan be increased by adding small quantities of chromium to it. Chromium steelalloys (mixtures containing one or more metals) are used to make mail platingfor tanks and warships. They are also used for ball bearings and the hardcutting edges of high-speed machine tools.Nickel is highly resistant to electric current and is ofttimes added tochromium steels to make them easier to work. For example, stainless steelsinks can be pressed out from flat sheets of steel that can contain 18 percentchomium and 8 percent nickel.When nickel is mixed with chromium, the resulting metal can standvery high temperatures without corroding. For example, the heating elements oftoasters can be made from an alloy that is 80 percent nickel and 20 percentchromium. This metal operates at a temperature of about 1380 degreesFahrenheit (750 degrees Celsius).Chromium was discovered in 1798 by the French chemist NicolasVauquelin. He chose the name chromium from the Greek wo rd chroma, which meanscolor. Chromium was a good choice of name, many chromium compounds are brightlycolored. Rubies are red and emeralds are green because they contain chromiumcompounds.Some of the brightest colors in the artists palette contain chromium.Chrome yellow is made from a substance which contains chromium, lead, andoxygen. atomic number 30 yellow contains zinc, chromium and oxygen. Chrome red is anotherchromium compound. Chrome green is used in paints and in printing cotton