What are the three main subatomic particles in an atom?

The three main subatomic particles in an atom are protons, neutrons, and electrons. Protons are positively charged particles found in the nucleus of the atom, contributing to the overall mass and defining the element's identity through the atomic number. Neutrons, which are neutral particles also located in the nucleus, contribute to the mass of the atom and play a key role in stabilizing the nucleus. Electrons are negatively charged particles that orbit the nucleus in various energy levels or shells, and they are essential for chemical reactions and bonding between atoms.

The other options include particles that are not considered fundamental subatomic components of atoms. Muons are elementary particles similar to electrons but are not found within atoms as stable constituents. Positrons are the antimatter counterparts of electrons and are not typically classified as fundamental components of normal matter atoms. Ions are charged atoms or molecules that have gained or lost electrons, which means they are not subatomic particles themselves but rather states of atoms based on their electron count. Thus, only protons, neutrons, and electrons are recognized as the primary subatomic particles that make up an atom.