The three main subatomic particles that make up an atom are ________.

• A. protons, neutrons, and electrons
• B. neutrons, electrons, and photons
• C. protons, neutrons, and alpha particles
• D. protons, electrons, and positrons

Answer: (A)

Verified step by step guidance

1. Recall that an atom is composed of smaller particles called subatomic particles, which determine its structure and properties.
2. Identify the three main subatomic particles that are universally accepted as constituents of an atom: protons, neutrons, and electrons.
3. Understand that protons carry a positive charge and are found in the nucleus of the atom.
4. Recognize that neutrons have no charge (are neutral) and are also located in the nucleus alongside protons.
5. Know that electrons carry a negative charge and orbit the nucleus in electron clouds or shells.