The fundamental particle found in the nucleus of an atom that has no charge is called a neutron. Neutrons, along with protons, make up the atomic nucleus. While protons have a positive charge, neutrons are electrically neutral, contributing to the atomic mass but not affecting the charge of the atom. Understanding neutrons is essential in nuclear physics and chemistry, as they play a crucial role in determining an element's isotopes and stability. They are also involved in nuclear reactions and atomic structure.