**Correct Option: C. Proton** ### Detailed Explanation: 1. **Understanding Atomic Structure**: - Atoms are the basic building blocks of matter and consist of three main types of subatomic particles: protons, neutrons, and electrons. - Protons and neutrons are found in the nucleus (the center of the atom), while electrons orbit around the nucleus. 2. **Charge of Subatomic Particles**: - **Protons** carry a positive charge (+1). - **Neutrons** are neutral, meaning they have no charge (0). - **Electrons** carry a negative charge (-1). - The overall charge of an atom is determined by the balance between the number of protons and electrons. In a neutral atom, the number of protons equals the number of electrons, resulting in no overall charge. 3. **Role of Protons in the Nucleus**: - The nucleus of an atom is positively charged due to the presence of protons. Since neutrons do not contribute to the charge, the positive charge of the nucleus is solely due to protons. - For example, in a hydrogen atom, there is one proton in the nucleus, giving it a +1 charge. In a carbon atom, there are six protons, resulting in a +6 charge from the protons alone. 4. **Why the Other Options Are Incorrect**: - **A. Electron**: Electrons are negatively charged particles. They do not contribute to the positive charge of the nucleus; instead, they balance the positive charge of protons in a neutral atom. - **B. Neutron**: Neutrons are neutral particles and do not carry any charge. While they contribute to the mass of the nucleus, they do not affect its charge. - **D. Positron**: A positron is the antimatter counterpart of an electron and carries a positive charge. However, positrons are not found in the nucleus of atoms under normal conditions and are not a fundamental component of atomic structure. ### Summary of Key Points: - The positive charge of an atomic nucleus is due to protons. - Protons are positively charged, while neutrons are neutral and electrons are negatively charged. - The balance of protons and electrons determines the overall charge of an atom. - Neutrons and electrons do not contribute to the positive charge of the nucleus. ### Revision Summary: - Protons are responsible for the positive charge of the nucleus. - Neutrons are neutral and do not affect the charge. - Electrons are negatively charged and balance the positive charge of protons in a neutral atom. - Positrons are not part of the atomic structure in normal conditions.