Which particles are found in the nucleus of an atom?

The nucleus of an atom is composed of protons and neutrons, collectively known as nucleons. Protons carry a positive charge, while neutrons are neutral particles. The presence of protons in the nucleus determines the atomic number of an element, which defines the element itself, while neutrons contribute to the mass of the atom and can influence its stability.

Electrons, which are negatively charged particles, do not reside in the nucleus; instead, they orbit the nucleus in various energy levels or shells around it. Decision-making concerning atomic interactions and bonding primarily involves these outer shell electrons. This distinction is vital in understanding atomic structure and behavior at a fundamental level.

The only constituents of the nucleus are protons and neutrons, making the information provided by the correct answer essential for grasping basic atomic chemistry and physics principles.