Nuclear chemistry is a specialized branch of chemistry and physics that studies the composition and reactions of atomic nuclei. It examines the transformations that occur within the core of atoms, focusing primarily on nuclear reactions such as radioactive decay, nuclear fission, and nuclear fusion. These processes involve changes in the number of protons and neutrons within the nucleus, leading to the emission of particles and energy. The field is instrumental in understanding the stability of isotopes, the principles of transuranic element formation, and the kinetics of various energy-releasing reactions. Research in nuclear chemistry is vital for developing new radiopharmaceuticals for medical imaging and treatment, and for analyzing the isotopic composition of materials from geological, environmental, or astronomical sources.