What is the collective term for protons and neutrons within an atom?

The term "nucleons" refers to the particles found in the nucleus of an atom, which encompasses both protons and neutrons. Protons carry a positive charge, while neutrons have no charge, together forming the core of an atom and contributing to its mass. By definition, nucleons are specifically those two types of particles found in the atomic nucleus.

Electrons are not included in this term, as they are found in the electron cloud surrounding the nucleus and do not contribute to the mass of the nucleus in the same way. "Nuclei" refers to the plural form of nucleus and describes entire atomic centers rather than the constituent particles. Quarks are the fundamental constituents of protons and neutrons, but they are not the collective term used to describe the protons and neutrons themselves. Thus, nucleons is the correct choice, accurately identifying the collective nature of protons and neutrons in atomic structure.