Which of the following correctly identifies the three main subatomic particles found in an atom?

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

Answer: (D)

Verified step by step guidance

1. Recall that atoms are 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 and muons are not considered main subatomic particles of an atom; photons are particles of light, and muons are elementary particles similar to electrons but heavier and unstable.
4. Recognize that positrons are the antimatter counterparts of electrons and are not part of the normal atomic structure.
5. Conclude that the correct set of the three main subatomic particles found in an atom is proton, neutron, and electron.