What particles are found in the nucleus of an atom?

• A. Electrons
• B. Protons
• C. Protons and neutrons
• D. Neutrons

Answer: (C)

Particles found in the nucleus are protons and neutrons, together called nucleons. They stay tightly packed at the center of the atom, forming the tiny core that holds most of the atom’s mass. Electrons, in contrast, orbit around the nucleus in regions surrounding it and contribute very little to the atom’s mass. The number of protons defines the element, while the neutrons can vary to form different isotopes, all sharing the same nucleus structure with protons and neutrons. So the nucleus contains both types of nucleons, not just one or the other, and not the electrons.