The subatomic particle with a positive charge is the proton. Protons are found in the nucleus of an atom, along with neutrons, which are neutral particles. The number of protons in the nucleus determines the atomic number of an element and thus its identity. For example, hydrogen has one proton, while carbon has six. The positive charge of protons plays a crucial role in determining how atoms interact, as they attract negatively charged electrons, maintaining the overall atomic structure and contributing to the electrical properties of elements.