electrons and neutrons. protons and neutrons. protons and electrons. protons, neutrons, and electrons.
I gave my students this multiple choice question: Neutral atoms have an equal number of

Only one answer is correct among these 4 choices:
- electrons and neutrons.
- protons and neutrons.
- protons and electrons.
- protons, neutrons, and electrons.

Could you tell me which one is correct?

protons and electrons.