What fundamental particle carries a positive charge?

The fundamental particle that carries a positive charge is the proton. Protons are subatomic particles found in the nucleus of an atom, and they play a crucial role in determining the atomic number, which defines the identity of the element. Each proton has a charge of +1 elementary charge, which is essential in balancing the negative charge of electrons in an atom, thus contributing to the overall charge neutrality of most atoms.

Neutrons, in contrast, are neutral particles that do not carry any charge, while electrons carry a negative charge. The nucleus itself is not a particle but rather the central core of an atom that contains protons and neutrons. Therefore, in the context of this question, the proton is the only particle listed that carries a positive charge.