What do neutrons contribute to an atom?

Neutrons contribute to the atomic mass of an atom. Atomic mass is essentially the total number of protons and neutrons present in the nucleus of an atom. Since neutrons are neutrally charged particles, they do not affect the overall charge of the atom but do add mass. The atomic number, on the other hand, is determined solely by the number of protons in the nucleus, which defines the element itself. The electron count reflects the number of electrons that balance the protons in a neutral atom but does not involve neutrons at all. Thus, neutrons play a critical role in increasing atomic mass while not influencing the charge or the atomic identity directly.