Final answer:
The nucleus contains two types of subatomic particles, protons and neutrons, which are collectively known as nucleons. Protons are positively charged, while neutrons carry no charge, and both contribute to the mass and stability of an atom.
Step-by-step explanation:
The subatomic particles found in the nucleus of an atom are protons and neutrons. Protons have a positive electric charge, while neutrons are neutral. Both fall under the category of nucleons and are densely packed within the nucleus, contributing to the majority of the atom's mass. The protons determine the atomic number of an element and its identity, while the number of both protons and neutrons together is referred to as the mass number. This mass can be expressed in unified atomic mass units (u), with 1 u equal to 1.6605 × 10-27 kg or 931.46 MeV/c².
Despite their common features, such as similar masses, protons and neutrons have distinctive roles within the atom and contribute to the observable properties and stability of atoms. Neutrons serve to buffer the electrostatic forces between protons which allow nuclei to be more stable. Together, these nucleons form a wide variety of nuclides, each with specific numbers of protons and neutrons, giving rise to all the known elements in the universe.