Radioisotopes are atoms that have unstable nuclei, resulting in them emitting radiation in the form of alpha, beta, or gamma rays. These radioactive isotopes are used in a variety of applications, including medical imaging and treatment, scientific research, industrial processes, and environmental monitoring. Radioisotopes are commonly used in nuclear medicine for diagnostic imaging, such as PET scans and thyroid scans, as well as in cancer therapy. They are also used in dating geological materials, tracing environmental pollutants, and studying metabolic processes in living organisms. The use of radioisotopes has revolutionized various fields of science and technology, providing valuable tools for understanding and improving our world.