what are the application of isotopes

an isotope of uranium is used to produce nuclear energy

an isotope of iodine is used to treat goitre

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Applications of isotopes

[edit]Purification

Several applications exist that capitalize on properties of the various isotopes of a given element. Isotope separation is a significant technological challenge, particularly with heavy elements such as uranium or plutonium. Lighter elements such as lithium, carbon, nitrogen, and oxygen are commonly separated by gas diffusion of their compounds such as CO and NO. The separation of hydrogen and deuterium is unusual since it is based on chemical rather than physical properties, for example in the Girdler sulfide process. Uranium isotopes have been separated in bulk by gas diffusion, gas centrifugation, laser ionization separation, and (in the Manhattan Project) by a type of production mass spectrometry.

[edit]Use of chemical and biological properties

Isotope analysis is the determination of isotopic signature, the relative abundances of isotopes of a given element in a particular sample. For biogenic substances in particular, significant variations of isotopes of C, N and O can occur. Analysis of such variations has a wide range of applications, such as the detection of adulteration of food products or the geographic origins of products using isoscapes. The identification of certain meteorites as having originated on Mars is based in part upon the isotopic signature of trace gases contained in them.
Isotopic substitution can be used to determine the mechanism of a chemical reaction via the kinetic isotope effect.
Another common application is isotopic labeling, the use of unusual isotopes as tracers or markers in chemical reactions. Normally, atoms of a given element are indistinguishable from each other. However, by using isotopes of different masses, even different nonradioactive stable isotopes can be distinguished by mass spectrometry orinfrared spectroscopy. For example, in 'stable isotope labeling with amino acids in cell culture (SILAC)' stable isotopes are used to quantify proteins. If radioactive isotopes are used, they can be detected by the radiation they emit (this is called radioisotopic labeling).

[edit]Use of nuclear properties

A technique similar to radioisotopic labeling is radiometric dating: using the known half-life of an unstable element, one can calculate the amount of time that has elapsed since a known level of isotope existed. The most widely known example is radiocarbon dating used to determine the age of carbonaceous materials.
Several forms of spectroscopy rely on the unique nuclear properties of specific isotopes, both radioactive and stable. For example, nuclear magnetic resonance (NMR) spectroscopy can be used only for isotopes with a nonzero nuclear spin. The most common isotopes used with NMR spectroscopy are ¹H, ²D,¹⁵N, ¹³C, and ³¹P.
Mössbauer spectroscopy also relies on the nuclear transitions of specific isotopes, such as ⁵⁷Fe.
Radionuclides also have important uses. Nuclear power and nuclear weapons development require relatively large quantities of specific isotopes. Nuclear medicine and radiation oncology utilize radioisotopes respectively for medical diagnosis and treatment.

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Daer Friend,
Let's imagine a pair of identical twins. These twins have the same temperament, and since they're identical, it is very hard to tell them apart unless you examine them closely. When it is time for their annual physical, the twins need to step on a weighing scale, and when they do, one weighs slightly more than the other. In terms of chemistry, we can say that these twins are like isotopes of each other.

Atoms and elements are made of protons, neutrons and electrons. The nucleus is made of protons and neutrons, and the electrons surround the nucleus, as shown in the illustration below. The sum of the number of protons and the number of neutrons is equal to the atomic mass.

In a given element, the number of neutrons can be different from each other, while the number of protons is not. These different versions of the same element are called isotopes. Isotopes are atoms with the same number of protons but that have a different number of neutrons. Since the atomic number is equal to the number of protons and the atomic mass is the sum of protons and neutrons, we can also say that isotopes are elements with the same atomic number but different mass numbers.

Let us take a look at an example.

Isotopes of Hydrogen

The three are all isotopes of hydrogen. As you can see, they have the same atomic number, or number of protons, (number at the lower left of the element) but different atomic masses (number at the upper left of the element).

The number of neutrons can be calculated by calculating the difference between the atomic mass and atomic number. We can see that for the isotopes of hydrogen, they have varying number of neutrons. For protium, the number of neutrons is zero, for deuterium, the number of neutrons is one, and for tritium, the number of neutrons is two.

Going back to our comparison with identical twins, we can say that these three isotopes of hydrogen are like identical triplets of each other - they may appear to be identical outside, but they are different inside, and they also have different names.

Isotopes of Carbon

A very popular element, carbon, also has isotopes. There are three isotopes of carbon: carbon-12, carbon-13 and carbon-14. The numbers that are after the carbon refer to the atomic mass.

The most common and abundant isotope of carbon is carbon-12. Looking at the percentages below each carbon isotope, we see that almost 98.9 % of the carbon that is found is in the form of carbon-12. The least abundant form of carbon is carbon-14, with an abundance of less than 0.0001%. If we calculate the number of neutrons for each carbon isotope, we can see that they differ from each other. For carbon-12, we have 6 neutrons, for carbon-13, we have 7 neutrons and for carbon-14, we have 8 neutrons.

You may notice if we look at the atomic masses of elements in the periodic table that they are rarely ever whole numbers, just like for carbon where the atomic mass is 12.011. This is because the atomic mass of carbon is based on the average atomic masses of its isotopes and the abundance of each isotope.

Types of Isotopes

There are two main types of isotopes and these are radioactive isotopes and stable isotopes. Stable isotopes have a stable combination of protons and neutrons, so they have stable nuclei and do not undergo decay. These isotopes do not pose dangerous effects to living things, like radioactive isotopes.

They are typically useful when performing experiments in the environment and in the field of geochemistry. These isotopes can help determine the chemical composition and age of minerals and other geologic objects. Some examples of stable isotopes are isotopes of carbon, potassium, calcium and vanadium.

Radioactive isotopes have an unstable combination of protons and neutrons, so they have unstable nuclei. Because these isotopes are unstable, they undergo decay, and in the process can emit alpha, beta and gamma rays.

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APPLICATIONS OF RADIOACTIVE ISOTOPES Kunstliche Radioaktive Isotope in Physiologie Diagnostik und Therapie. Edited by H. Schwiegk and F. Turba. In two volumes. Second edition. (Vol. I: Pp. 1,327+xliv; illustrated. Vol. II: Pp. 1,248+xxii; illustrated. Price for 2 vols. DM. 398.) Berlin, Gottingen, Heidelberg: SpringerVerlag. 1961. The second edition of this encyclopaedic work on the biological applications of radioactive isotopes forms a reference text of the greatest scope and value. The first volume deals mainly with basic principles and methods and with biochemical studies with labelled materials. It includes reviews of protection techniques (by Hug and Muth) and handling methods, of autoradiography, and of biological effects of radiation (Lamerton), and of isotopes deposited in tissues (Odell and Upton). The biochemical section contains useful reviews of labelling techniques, of R.N.A. and D.N.A. synthesis (Ochoa, and Kornberg), porphyrins (Shemin), steroids (Dorfman), and thyroid hormones (Roche and Michel). The first part of the second volume deals with radioisotope studies of the metabolism of various elements and tissues, with clinically useful sections on the metabolism of iron and of vitamin B12 in man, circulatory studies (Waser), thyroid investigation (Bansi), and the localization or diagnosis of various types of tumour in man (Mullet). This section also contains extensive reviews of work on virus metabolism, immune mechanisms, photosynthesis, genetic mechanisms, and the metabolism of micro-organisms. In so rich a source of information it is unfair to expect the balance of emphasis from different contributors on different subjects to satisfy every reader. It seems, for example, anomalous that nerve and muscle metabolism should receive 23 and 50 pages, while that of bone and teeth together are dealt with in six, with short references also under particular bone-seekers and in the review of Odell and Upton. In general, however, the balance is better than is often achieved in compilations from numerous authors, and the editing has clearly been active and effective. Therapeutic applications are dealt with in authoritative reviews by Becker and Scheer on various types of local injection, by Heilmeyer and Keiderling on haematology, by Horst on thyroid cancer, and Muller on other forms of therapy, with shorter sections on hyperthyroidism by Oeser, Billion, and Kuhne, and on pituitary ablation by John Lawrence and co-workers. The whole work is of well over 2,000 pages (about a quarter in English), with ample bibliographies and an excellent general format and presentation. The subject index is of 269 pages. E. E. POCHIN. LEUCOCYTIC FUNCTION Biological Activity of the Leucocytes. In Honour of Professor A. Vannotti. Ciba Foundation Study Group No. 10. Editors for the Ciba Foundation: G. E. W. Wolstenholme, O.B.E., M.A., M.B., M.R.C.P., and Maeve O'Connor, B.A. (Pp. 120; illustrated. 12s. 6d.) London: J. and A. Churchill Ltd. 1961. This little volume contains the proceedings of a Ciba Foundation Study Group which met in March, 1961, under the chairmanship of Professor P. B. Medawar. Seven papers dealing with various aspects of leucocytic function were presented at the meeting, and these, together with a transcript of the discussions following them, are reproduced here. The topics include the role of human leucocytes in local defence reactions (Rebuck), immunological and possible haemopoietic activities of lymphocytes (Gowans, Yoffey), a study of metabolic changes in polymorphs and monocytes during phagocytosis (Karnovsky), and patterns of metabolism in leucocytes within and outside the circulation (Vanotti, Frei, Antonioli). The papers are not critical reviews but mostly accounts of reseach work, and such previously unpublished information as they contain might more appropriately find a place in ordinary scientific journals. F. G. J. HAYHOE.

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