What is the primary role of neutrons in an atom?

The primary role of neutrons in an atom is to add mass without carrying a charge. Neutrons, along with protons, make up the nucleus of an atom, and they contribute to the overall mass of the atom. Although they do not influence the electrical charge of the atom since they are neutral, their presence is crucial in stabilizing the nucleus. The number of neutrons relative to the number of protons can also affect the stability of the atom, leading to different isotopes. The mass number of an atom, which defines the weight of the atom, is determined by the total number of protons and neutrons, thereby highlighting the important role that neutrons play in adding mass to the atom.