Cobalt-60 Nuclear Generating Station. The cobalt targets are substituted here for a small number of fuel assemblies. After entering a living mammal (such as a human being), some of the is excreted in feces. The remainder is taken up by tissues, mainly the liver, kidneys, and bones, where the prolonged exposure to gamma radiation can cause cancer. Over time, the absorbed cobalt is eliminated in urine. Cobalt is an element used to make steel. Uncontrolled disposal of in scrap metal is responsible for the radioactivity found in several iron-based products. In August 2012, Petco recalled several models of steel pet food
Chemical element whole number. For example, the relative atomic mass of chlorine is 35.453 u, which differs greatly from a whole number as it is an average of about 76% chlorine-35 and 24% chlorine-37. Whenever a relative atomic mass value differs by more than 1% from a whole number, it is due to this averaging effect, as significant amounts of more than one isotope are naturally present in a sample of that element. Chemists and nuclear scientists have different definitions of a "pure element". In chemistry, a pure element means a substance whose atoms all (or in practice almost all) have the