Radioactivity from radiation processing, characteristics

Characteristics of Radioactivity Resulting from Radiation Processing... 

Radiation from radioactive nuclides is used to detect changes in density or other characteristics of materials, to promote chemical, physical, or biological changes, and to provide a source of thermal energy. Some radioactive materials find use in industry, research, and medicine as tracers for physical, chemical, and biological processes.58... 

In 1898, in Cambridge, England, a New Zealander, Ernest Rutherford, demonstrated that there were at least two different types of radiation with different penetrating power. He called these alpha and beta radiation. He subsequentiy worked at McGill University in Montreal, Canada, and found more radioactive elements different types of radium and thorium, and actinium. He proposed that these were links in chains of radioactive materials, called the transformation theory. Rutherford and his colleague, Frederic Soddy, described that the rate of decay of radioactive elements were characteristic of the element, and came to be known as half-life. Decay follows the law of probability. Over a given period of time, each atom has a certain probability of decaying, a process that results from the random movements of the subatomic components of the radioactive atoms. This was the first instance in physics of a truly unpredictable phenomenon. The decay of a radioactive atom was probabilistic. 

Many radioactive compounds can be used as tracers or indicators becanse they emit a characteristic radiation which allows their presence to be detected, even in very minute quantities. Chemical and biochemical reactions and many physical processes are largely insensitive to the difference in nuclei which exists between the stable and radioactive isotopes—in this case P and P. It is therefore possible to mix a small nnmber of radioactive atoms with the stable ones, and incorporate them in the same chemical compound. The emission of radiation from the radioactive species enables them to be detected and followed in the course of reactions which the given compound may undergo. 

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