1. Electricity Generation: Nuclear power plants use nuclear fission (the splitting of atoms) to produce heat, which is then used to generate steam and power turbines that produce electricity.

2. Medical Imaging and Treatment: Nuclear medicine utilizes radioactive isotopes for diagnostic imaging (like PET scans) and treatment of certain cancers (like radiation therapy).

3. Scientific Research: Nuclear reactions are used in a wide range of scientific research, including dating ancient artifacts (radiocarbon dating), studying the properties of matter, and exploring the universe through nuclear physics.