Uses of isotopes in medicine and radiochemical dating

Medical Isotopes: ISOTOPES An isotope is one of two or more species of atoms of a chemical element with the same atomic number same number or protons in the nucleus and position in the periodic table and nearly identical chemical behavior but with different atomic masses and physical properties. Every chemical element has one or more isotopes. An atom is first identified and labeled according to the number of protons in its nucleus.

Radioactive isotope

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 effective tracers because their radioactivity is easy to detect. A tracer A substance that can be used to follow the pathway of that substance through a structure.

For instance, leaks in underground water pipes can be discovered by running some tritium-containing water through the pipes and then using a Geiger counter to locate any radioactive tritium subsequently present in the ground around the pipes. Recall that tritium is a radioactive isotope of hydrogen. Tracers can also be used to follow the steps of a complex chemical reaction. After incorporating radioactive atoms into reactant molecules, scientists can track where the atoms go by following their radioactivity.

One excellent example of this is the use of carbon to determine the steps involved in photosynthesis in plants. We know these steps because researchers followed the progress of carbon throughout the process. 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 and a certain amount of its daughter isotope, we can conclude that a certain fraction of the original uranium has radioactively decayed. If half of the uranium has decayed, then the rock has an age of one half-life of uranium, or about 4. 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, is particularly useful in determining the age of once-living artifacts. A tiny amount of carbon 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; as time passes the carbon that was in the tissues decays.

The half-life of carbon is 5, y. If a once-living artifact is discovered and analyzed many years after its death and the remaining carbon 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 Figure 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, y.

In , several groups of scientists used carbon dating to demonstrate that the Shroud of Turin was only — y. Many people still cling to a different notion, despite the scientific evidence. 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 or cesium 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. Radioactive isotopes have numerous medical applications—diagnosing and treating illness and diseases.

One example of a diagnostic application is using radioactive iodine to test for thyroid activity Figure 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 I 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 has a half-life of only 8 d, so the potential for damage due to exposure is minimal. Technetium 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. Scan courtesy of Myo Han, http: Very little radioactive material is needed in these diagnostic techniques because the radiation emitted is so easy to detect.

However, therapeutic applications usually require much larger doses because their purpose is to preferentially kill diseased tissues. For example, if a thyroid tumor were detected, a much larger infusion thousands of rem, as opposed to a diagnostic dose of less than 40 rem of iodine could help destroy the tumor cells. Similarly, radioactive strontium is used to not only detect but also ease the pain of bone cancers. Table In addition to the direct application of radioactive isotopes to diseased tissue, the gamma ray emissions of some isotopes can be directed toward the tissue to be destroyed.

Cobalt is a useful isotope for this kind of procedure. Wine lovers put some stock in vintages , or the years in which the wine grapes were grown before they were turned into wine. Wine can differ in quality depending on the vintage. Some wine lovers willingly pay much more for a bottle of wine with a certain vintage. But how does one verify that a bottle of wine was in fact part of a certain vintage? Is the label a fake?

Is that stash of wine found in the basement of a French chateau really from the s, or was it made in ? This wine label from a bottle of wine claims a vintage of Is the wine really from this vintage, or is it a fake? Radioactivity can help determine the answer. Cesium is a radioactive isotope that has a half-life of It was introduced into the atmosphere in the s and s by the atmospheric testing of nuclear weapons by several countries after World War II.

A significant amount of cesium was released during the Chernobyl nuclear disaster in As a result of this atmospheric contamination, scientists have precise measurements of the amount of cesium available in the environment since Some of the isotope of cesium is taken up by living plants, including grape vines. Using known vintages, oenologists wine scientists can construct a detailed analysis of the cesium of various wines through the years. It may be a good wine, but it is almost definitely not over 60 years old.

Define tracer and give an example of how tracers work. Name two isotopes that have been used in radioactive dating. The current disintegration rate for carbon is A sample of burnt wood discovered in an archeological excavation is found to have a carbon disintegration rate of 3. If the half-life of carbon is 5, y, approximately how old is the wood sample?

A small asteroid crashes to Earth. After chemical analysis, it is found to contain 1 g of technetium to every 3 g of ruthenium, its daughter isotope. If the half-life of technetium is , y, approximately how old is the asteroid? Describe how iodine is used to both diagnose and treat thyroid problems. List at least five organs that can be imaged using radioactive isotopes. Which radioactive emissions can be used therapeutically? Which isotope is used in therapeutics primarily for its gamma ray emissions?

A tracer is a radioactive isotope that can be detected far from its original source to trace the path of certain chemicals. Hydrogen-3 can be used to trace the path of water underground. If the initial amount of a radioactive isotope is known, then by measuring the amount of the isotope remaining, a person can calculate how old that object is since it took up the isotope. The thyroid gland absorbs most of the iodine, allowing it to be imaged for diagnostic purposes or preferentially irradiated for treatment purposes.

Previous Section. Table of Contents. Next Section. Radioactive Dating Radioactive isotopes are useful for establishing the ages of various objects. Figure 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.

Medical Applications Radioactive isotopes have numerous medical applications—diagnosing and treating illness and diseases. Food and Drink App: Radioactivity in Wines Wine lovers put some stock in vintages , or the years in which the wine grapes were grown before they were turned into wine. Used by permission of Ralph E.

Key Takeaway Radioactivity has several practical applications, including tracers, medical applications, dating once-living objects, and preservation of food. Exercises Define tracer and give an example of how tracers work. Name two isotopes that have been used as tracers. Explain how radioactive dating works. What is a positive aspect of the irradiation of food? What is a negative aspect of the irradiation of food? Answers A tracer is a radioactive isotope that can be detected far from its original source to trace the path of certain chemicals.

Radioactive isotope, also called radioisotope, radionuclide, or radioactive nuclide, any of several species of How are radioactive isotopes used in medicine?. The first uses considered were isotopes in medicine although greater emphasis . Among the subjects discussed were the applications of Carbon 14 for dating . The majority of the isotopes were obtained from the Radiochemical Centres at .

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. A radioactive isotope, also known as a radioisotope, radionuclide, or radioactive nuclide, is 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. Every chemical element has one or more radioactive isotopes.

Isotopes in radiochemical dating Aprenda a next, announces his killer.

Radioactive isotopes have many useful applications in a wide variety of situations, for example, they can be used within a plant or animal to follow the movement of certain chemicals. In medicine, they have many uses, such as imaging, being used as tracers to identify abnormal bodily processes, testing of new drugs and conducting research into cures for disease. Plants take up phosphorus-containing compounds from the soil through their roots.

The attributes of naturally decaying atoms, known as radioisotopes, give rise to several applications across many aspects of modern day life see also information paper on The Many Uses of Nuclear Technology. There is widespread awareness of the use of radiation and radioisotopes in medicine, particularly for diagnosis identification and therapy treatment of various medical conditions. In developed countries a quarter of the world population about one person in 50 uses diagnostic nuclear medicine each year, and the frequency of therapy with radioisotopes is about one-tenth of this. Nuclear medicine uses radiation to provide information about the functioning of a person's specific organs, or to treat disease. In most cases, the information is used by physicians to make a quick diagnosis of the patient's illness. The thyroid, bones, heart, liver, and many other organs can be easily imaged, and disorders in their function revealed.

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 effective tracers because their radioactivity is easy to detect. A tracer A substance that can be used to follow the pathway of that substance through a structure. For instance, leaks in underground water pipes can be discovered by running some tritium-containing water through the pipes and then using a Geiger counter to locate any radioactive tritium subsequently present in the ground around the pipes. Recall that tritium is a radioactive isotope of hydrogen. Tracers can also be used to follow the steps of a complex chemical reaction. After incorporating radioactive atoms into reactant molecules, scientists can track where the atoms go by following their radioactivity. One excellent example of this is the use of carbon to determine the steps involved in photosynthesis in plants.

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Uses of Isotopes
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