Radioactive isotopes :
An atom with an unstable nucleus, which emits particulate or electromagnetic radiation
(radioactive emission) to achieve greater stability is said to be radioactive atom.
A radioactive isotope is one in which the nucleus decays spontaneously, giving off particles and energy. When the decay leads to a change in the number of protons, it transforms the atom to an atom of a different element. For example, radioactive carbon decays to form nitrogen.
Radioactive isotopes have many useful applications in biology. Radioactive isotopes are also useful as tracers to follow atoms through metabolism, the chemical processes of an organism, etc.
New element 117 discovered–Ununseptium
Ununseptium is the second–heaviest element of all created so far and is radioactive,
having a half–life that appears to be less than one second.
Applications of Radioactive isotopes: Radiocarbon dating (or simply carbon dating) is a technique that uses the decay of carbon–14 (14C) to estimate the age of organic materials, such as wood and leather, up to about 58,000 to 62,000 years. The dating method is based on the fact that carbon is found in various forms, including the main stable isotope (12C) and an unstable isotope (14C).
Radioisotopes can be used to help understand chemical and biological processes in plants. Food irradiated by exposing it to the gamma rays of a radioisotope – one that is widely used is cobalt–60. The energy from the gamma ray passing through the food is enough to destroy many disease – causing bacteria as well as those that cause food to spoil, but is not strong enough to change the quality, flavor or texture of the food. It is important to keep in mind that the food never comes in contact with the radioisotope and is never at risk of becoming radioactive.
Nuclear medicine uses small amounts of radiation to provide information about a person's body and the functioning of specific organs, ongoing biological processes, or the disease state of a specific illness Radioactive isotopes and radioactively labeled molecules are used as tracers to identify abnormal bodily processes. This is possible because some elements tend to concentrate (in compound form) in certain parts of the body – iodine in the thyroid, phosphorus in the bones and potassium in the muscles. When a patient is injected with a compound doped with a radioactive element, a special camera can take pictures of the internal workings of the organ. Analysis of these pictures by a specialist doctor allows a diagnosis to be made.