Isotopes are atoms of an element that have the same atomic number (that is, same number of protons), but different atomic mass (that is, different number of neutrons). Isotopes find different uses in science, technology, medical sciences, military applications, etc. The most common and widely known application of isotope is in nuclear fission. Uranium-235, an isotope of uranium (U-238 is the common form) undergoes nuclear fission and generates large amount of energy. This energy can be used in electricity generation (in a nuclear power plant) or as a nuclear bomb (fission bomb). Isotopes (such as, rubidium-82, nitrogen-13, indium-111, etc.) are used in nuclear imaging. Conditions, such as hyperthyroidism and thyroid cancer can be treated by ionizing radiation of isotopes such as iodine-131. There are a number of other applications of isotopes in areas such as archaeology, physics, geology, etc.
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