What are the three parts that an atom consists of?

• A. Protons and Neutrons
• B. Electrons and Protons
• C. Protons, Neutrons, Electrons
• D. Neutrons and Electrons

Answer: (C)

Atoms are built from three main parts: protons, neutrons, and electrons. The nucleus contains protons and neutrons; protons carry a positive charge while neutrons have no charge. Surrounding the nucleus are electrons, which are negatively charged and form the electron cloud that defines much of an atom’s behavior in reactions. The combination and balance of these three components determine the identity and properties of the atom. If you leave out any one of them, you’re describing an incomplete picture of the atom—hence the correct choice includes all three.