What particle in the nucleus of an atom has a positive charge?

The particle in the nucleus of an atom with a positive charge is the proton. Protons are one of the three main subatomic particles that make up an atom, the other two being neutrons, which have no charge, and electrons, which carry a negative charge. The presence of protons in the nucleus is crucial because they define the atomic number of an element. This atomic number determines the identity of the element itself; for instance, an atom with one proton is hydrogen, while an atom with six protons is carbon.

In atomic structure, protons are bound tightly together with neutrons through the strong nuclear force, creating a dense nucleus at the center of the atom. The positive charge of protons also plays a fundamental role in the overall electrical balance of the atom, as it attracts negatively charged electrons that orbit the nucleus, allowing the structure of the atom to be stable.

Understanding the role of protons helps clarify many concepts in chemistry and physics, including electrical charge, atomic interactions, and even the formation of ions when atoms gain or lose electrons.