Which Particles That Make Up An Atom Are Involved In Nuclear Reactions? Protons Only Protons And Neutrons Electrons Only Electrons And Neutrons. The mass of electrons is very small and often not considered to be significant. In nuclear reactions, the particles involved are primarily protons and neutrons, which are collectively known as nucleons.

The mass of electrons is very small and often not considered to be significant. Protons, neutrons, and electrons are the three main subatomic particles that make up an atom. These particles reside in the nucleus of an atom.