Radioisotopes are formed by Isotopes, which are atoms with the same atomic number and different mass numbers. Some Types of radioisotopes are Radioactive sodium carbon, phosphorous, Iodine, Gold.
Examples of natural radioisotopes are 238 U (uranium), 40 K (potassium), 232 Th (thorium) and their child nuclei (obtained by radioactive decay of the previous ones) 226 Ra (radio), 222 Rn (radon) and 218 Po (polonium).
Nuclei which do not emit radiations naturally are called stable nuclei. In general, most of the nuclei with atomic numbers 1 to 82 are stable nuclei.
While the elements whose atomic number is greater than 82 are naturally unstable. They emit different types of radiations, all the time, and hence continuously change from one type of element to another. The stable and non-radioactive elements can also be changed into radioactive elements by bombarding them with protons, neutrons or alpha particles. Such artificially produced radioactive elements are called radioactive isotopes or radioisotopes.
Here is some example of the production of radioisotopes:
Learn Also : Radioactivity
Uses of Radioisotopes
Radioisotopes have proved to be beneficial to mankind in the sphere of medicine and industry. These are unstable isotopes of the elements which are undergoing nuclear transmutations by themselves and are emitting radiations. These are produced by natural radioactivity as by artificial transmutations and have some chemical properties as their inactive counterparts.
List of radioisotopes
- Radioactive sodium carbon
These are some very important radioisotopes which are used in daily life. These are manufactured mainly by irradiating substances with neutrons in a nuclear reactor but they can also be made by bombardment with high energy particles from an accelerator.
See Also: Types of radiations
Uses of radioisotopes in medicine
Radioisotopes are used in medicine for diagnoses and treatment.
- Certain radioisotopes localize in certain parts of the body and cure those parts by the radiation they emit for example. Iodine localizes in the thyroid glands. Hence for the treatment of thyroid glands, radio-iodine can be administrated to the patients. Similarly, radio-phosphorous which is a beta emitter can be used for curing skin diseases. It can be applied to the diseased surface of the body and will cure it slowly Radio. Cobalt has been used for curing cancer due to its n°-activity. It is implanted in the concerned parts in the form of needles.
- To study the way in which a certain foodstuff is absorbed by the body radio-isotopes are mixed with food (fat) and form their radioactivity it is noted whether they are secreted out with urine or absorbed by the body and it is also ascertained which parts of the body most absorb a particular food.
Learn aslo: Half-life
Uses of Radioisotopes in industry
- Detection of flows and cracks in heavy machinery. Heavy machinery parts are placed between a radioactive source and photographic film and radiations which pass through the part are allowed to produce their effects upon the photographic film. On developing the film the flaws and cracks will be elected because through these regions the absorption will be smaller than through other regions.
- Radio-isotopes can be used as gauges. The rate of flow of a fluid through a pipe that is dug beneath the surface of the earth can be measured from the rate of radioactive shown by it if a source is mixed with a smaller quantity of a radioactive isotope.
- Also, the leakage of fluid from the pipes can be detected if it is mixed a smaller quantity of radioisotopes at the source from where it is pumped in the pipes.
Learn more related topics of Nuclear Physics
Uses of radioisotopes in agriculture
- Radioisotopes can be used for killing the bacteria and dangerous insects from the plants and seeds.
- The rate of growth of roots of a plant can be measured by placing the radioactivity fertilizer at various depths in the soil. When the roots reach the depth the plant will show radioactivity
- The rate at which a certain food is absorbed by the plant can be found by mixing a small quantity of radio phosphorous with the fertilizer and noting the time after which a certain branch of the plant shows radioactivity.
- The process of photosynthesis in plants and fruits can be studied with the help of radioactive carbon. The process by the green plants absorb carbon dioxide and water in the presence of sunlight and form proteins, fats and carbon hydrates are called photosynthesis. During this process, oxygen is released. Plants are exposed to C14O2 in which C14 is radioactive and the same time after which a certain compound say (sugar) is formed in a certain fruit or plant is determined from the activity shown by it.
What are radioisotopes and their uses video)