Cadmium :: essays research papers fc

Cadmium, symbol, Cd, is a silvery white metallic chemical element with a faint blue tinge to it. It is the fifty-seventh most commonly found element in the earth. It was discovered by F. Stromeyer, in 1817, in Germany. Stromeyer was studying a sample of zinc carbonate which separated into a the new element ultimately called cadmium. The only cadmium materials, greenockite (cadmium sulfide) and otavile (cadmium carbonate) are found in zinc oxide and zinc carbonate. Cadmium, which is usually associated with zinc has some differences; some of which are that cadmium is softer and has a lower melting and boiling point than zinc. There are five basic states of cadmium. First, there is the regular raw metal cadmium. Then there is cadmium oxide which is formed by burning the raw metal in the air producing brown smoke. Cadmium oxide can also be formed by heating cadmium carbonate in acid or ammonia producing a brown powder. By doing this, cadmium and oxygen are being mixed. Cadmium carbonate is made by absorbing carbon dioxide into the raw metal or mixing cadmium salts with ammonium carbonate, forming a salt-like substance. Cadmium sulfide is made by mixing hydrogen sulfide with a solution of cadmium ions, resulting in a range of colors from lemon yellow to a deep red. Cadmium halides are compounds with complex cadmium ions in them to form varied structure solutions. The regular structure of a cadmium atom is that it has four electron shells with a total of 48 electrons in it. The main use for cadmium is to plate iron, steel and other metals, protecting them from corrosion. This method has been used since 1919. The use of cadmium has to be limited because it gives off large numbers of toxins into the environment. The use of cadmium has gradually decreased in order to help the environment. It is not used to plate food processing parts or ovens because of this. Cadmium may be found in some cereals, nuts and vegetables, but scientists doubt that, if taken is small quantities, it would prove harmful. Cadmium is also used for nickel-cadmium batteries and nuclear control rods. It is used in compounds, for example, with copper to harden them. Since the color of cadmium sulfide varies it is useful for