Why Are Radioisotopes Useful?
Radioisotopes have been present since the beginning of time, but their practical applications are just beginning to emerge. Many radioisotopes occur naturally, and humans can manufacture many more.
Radioisotopes have three unique characteristics that make them useful tools:
- They emit energy (radiation) in the form of rays or particles, which can penetrate substances of varying thicknesses such as paper, body tissue, or concrete. The rays, called “gamma rays,” are quite strong and can penetrate through substances as thick as three feet of concrete. On the other hand, a thin sheet of metal will stop a “beta” particle, and a single sheet of paper will stop an “alpha particle.”
- Their radiation is predictable. Over time, radioisotopes lose their radioactivity through the process of decay. Some radioisotopes decay in a fraction of a second, while others take millions of years; but the lifespan of each is well known and understood. (Decay is measured in “half-lives.” The half-life of a radioactive substance is the time it takes for a quantity of that substance to lose one-half of its radioactivity.)
- Radioisotopes of a chemical element have the same chemical properties as the non-radioactive atoms of that element. This makes it possible to “trace” a chemical element by adding a radioisotope of that element, something that is especially useful to doctors in diagnosing illnesses such as heart disease and cancer.
Radioisotopes have improved our methods of diagnosing and treating diseases and powering explorations of space. With radioisotopes, we can chart the course of events that occurred before historical records were kept. With radioisotopes, we can improve our environment, make better industrial products, grow bigger and better plants more economically, and preserve foods in a new way.
Scientists now realize that these are only a preview of things to come and that the future holds the promise of many new and innovative ways in which radioisotopes can improve our lives.
Links for more information.. http://www.ne.doe.gov/isotopes/neisotopes2a.html
