uses of radioactive isotopes in various fields
Answers
Explanation:
Radioactive isotope, also called radioisotope, radionuclide, or radioactive nuclide, any of several species of the same chemical element with different masses whose nuclei are unstable and dissipate excess energy by spontaneously emitting radiation in the form of alpha, beta, and gamma rays.
In industry, radioactive isotopes of various kinds are used for measuring the thickness of metal or plastic sheets; their precise thickness is indicated by the strength of the radiations that penetrate the material being inspected. They also may be employed in place of large X-ray machines to examine manufactured metal parts for structural defects. Other significant applications include the use of radioactive isotopes as compact sources of electrical power—e.g., plutonium-238 in spacecraft. In such cases, the heat produced in the decay of the radioactive isotope is converted into electricity by means of thermoelectric junction circuits or related devices.
The table lists some naturally occurring radioactive isotopes.
Some significant naturally occurring radioactive isotopes
isotope half-life (years, unless noted)
Source: National Nuclear Data Center, Brookhaven National Laboratory, NuDat 2.6 (2016).
3H 12.32
14C 5,700
50V >2.1 × 1017
87Rb. 4.81 × 1010
90Sr. 28.9
115In 4.41 × 1014
123Te. >9.2 × 1016
130Te. >3.0 × 1024
131I 8.0252 days
137Cs. 30.08
138La. 1.02 × 1011
144Nd. 2.29 × 1015
147Sm 1.06 × 1011
148Sm 7 × 1015
176Lu 3.76 × 1010
187Re. 4.33 × 1010
186Os 2 × 1015
222Rn. 3.8235 days
226Ra 1,600
230Th. 75,400
232Th. 1.4 × 1010
232U 68.9
234U. 245,500
235U. 7.04 × 108
236U. 2.342 × 107
237U. 6.75 days
238U. 4.468 × 109
hii there...!!!
Radioactive isotopes have a variety of applications. Generally, however, they are useful because either we can detect their radioactivity or we can use the energy they release.
Radioactive isotopes are useful for establishing the ages of various objects. The half-life of radioactive isotopes is unaffected by any environmental factors, so the isotope acts like an internal clock. For example, if a rock is analyzed and is found to contain a certain amount of uranium-235 and a certain amount of its daughter isotope, we can conclude that a certain fraction of the original uranium-235 has radioactively decayed. If half of the uranium has decayed, then the rock has an age of one half-life of uranium-235, or about 4.5 × 109 y. Many analyses like this, using a wide variety of isotopes, have indicated that age of the earth itself is over 4 × 109 y. In another interesting example of radioactive dating, hydrogen-3 dating has been used to verify the stated vintages of some old fine wines.
One isotope, carbon-14, is particularly useful in determining the age of once-living artifacts. A tiny amount of carbon-14 is produced naturally in the upper reaches of the atmosphere, and living things incorporate some of it into their tissues, building up to a constant, albeit very low, level. Once a living thing dies, it no longer acquires carbon-14; as time passes the carbon-14 that was in the tissues decays. (The half-life of carbon-14 is 5,370 y.) If a once-living artifact is discovered and analyzed many years after its death and the remaining carbon-14 is compared to the known constant level, an approximate age of the artifact can be determined. Using such methods, scientists determined that the age of the Shroud of Turin ; purported by some to be the burial cloth of Jesus Christ and composed of flax fibres, a type of plant) is about 600–700 y, not 2,000 y as claimed by some. Scientists were also able to use radiocarbon dating to show that the age of a mummified body found in the ice of the Alps was 5,300 y.
In 1989, several groups of scientists used carbon-14 dating to demonstrate that the Shroud of Turin was only 600–700 y. Many people still cling to a different notion, despite the scientific evidence.
Irradiation of Food
The radiation emitted by some radioactive substances can be used to kill microorganisms on a variety of foodstuffs, extending the shelf life of these products. Produce such as tomatoes, mushrooms, sprouts, and berries are irradiated with the emissions from cobalt-60 or cesium-137. This exposure kills a lot of the bacteria that cause spoilage, so the produce stays fresh longer. Eggs and some meat, such as beef, pork, and poultry, can also be irradiated. Contrary to the belief of some people, irradiation of food does not make the food itself radioactive.
Medical Applications
Radioactive isotopes have numerous medical applications—diagnosing and treating illness and diseases. One example of a diagnostic application is using radioactive iodine-131 to test for thyroid activity. The thyroid gland in the neck is one of the few places in the body with a significant concentration of iodine. To evaluate thyroid activity, a measured dose of 131I is administered to a patient, and the next day a scanner is used to measure the amount of radioactivity in the thyroid gland. The amount of radioactive iodine that collects there is directly related to the activity of the thyroid, allowing trained physicians to diagnose both hyperthyroidism and hypothyroidism. Iodine-131 has a half-life of only 8 d, so the potential for damage due to exposure is minimal. Technetium-99 can also be used to test thyroid function. Bones, the heart, the brain, the liver, the lungs, and many other organs can be imaged in similar ways by using the appropriate radioactive isotope.
Radioactive iodine can be used to image the thyroid gland for diagnostic purposes.
Some Radioactive Isotopes with Medical Applications
Isotope Use
32P cancer detection and treatment, especially in eyes and skin
59Fe anemia diagnosis
60Co gamma ray irradiation of tumors
99mTc* brain, thyroid, liver, bone marrow, lung, heart, and intestinal scanning; blood volume determination
131I diagnosis and treatment of thyroid function
133Xe lung imaging
198Au liver disease diagnosis
*The “m” means that it is a metastable form of this isotope of technetium.