In atomic physics, a neutron is a subatomic particle found in the nucleus of atoms, along with protons. It has no electric charge, and its mass is slightly larger than that of a proton. Neutrons are crucial in the processes of nuclear fission and nuclear fusion, and are used in many scientific experiments and applications, including in nuclear power plants and in the production of medical isotopes. The discovery of the neutron by Chadwick in 1932 revolutionized the understanding of the atomic nucleus and led to many advances in nuclear physics.