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					Cobalt My report is about the element Cobalt. Cobalt is the 27th element on the periodical table and has an atomic number of twenty-seven. It has a symbol of Co. Cobalt¹s atomic weight is 58.9332. It has a melting point of 1,490š C. and a boiling point of 2,900š C. Cobalt looks almost exactly like iron and nickel. Cobalt is between iron and nickel on the periodical table and found in only .001-.002 percent of the earth¹s crust. Cobalt was first found in the Harz Mountains. People in the silver mines dug up arsenic cobalt ores. Then, because they thought the ores contained copper, heated the ores releasing arsenic trioxides. Cobalt was named after the German kobold. A kobold was said to be an underground goblin or demon. In 1735 cobalt was identified. Cobalt is a white metal with a bluish cast. It is magnetic and very hard and does not tarnish. Cobalt has many uses and I will talk about some of them. It is a very expensive metal that is used in the manufacture of very many expensive alloys. Cobalt-iron alloys have very unique and special magnetic properties. For example, Hyperco is used as the nucleus in strong electromagnets. Alloys containing titanium, aluminum, cobalt and nickel can be made to become permanently magnetic. One alloy, called Stellite, is an alloy of cobalt, chromium, tungsten, and molybdenum. This alloy is extremely hard and keeps its hardness at extreme temperatures. It has many uses: cutting tools are made of it along with gas turbines. Zaire is the world¹s largest producer of cobalt with 65% of the world¹s reserve. Cobalt is a common trace element found in food. It is a component of vitamin B12. It is important to our health. But excessive amounts may cause nausea, damage to the heart, kidneys, and nerves, and even cause death. I think that Cobalt is a neat element. Before I did this report I knew nothing of Cobalt. Now I know how they use it as an alloy and in other ways.


				
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posted:11/25/2009
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