Which of the following lists the three main subatomic particles that make up an atom?

• A. Electron, photon, neutron
• B. Proton, positron, neutron
• C. Neutron, neutrino, proton
• D. Proton, neutron, electron

Answer: (D)

Verified step by step guidance

1. Recall that an atom is composed of three main subatomic particles: protons, neutrons, and electrons.
2. Understand the role of each particle: protons carry a positive charge, neutrons are neutral (no charge), and electrons carry a negative charge.
3. Identify that photons, positrons, and neutrinos are not considered main subatomic particles of an atom. Photons are particles of light, positrons are the antimatter counterparts of electrons, and neutrinos are neutral particles involved in nuclear reactions but not part of the atom's structure.
4. Compare the given options and recognize that only the list containing proton, neutron, and electron correctly represents the three main subatomic particles of an atom.
5. Conclude that the correct answer is the list: proton, neutron, electron.