Answer:
C. 2 protons, 2 electrons, and 1 neutron.
Step-by-step explanation:
An atom that has no charge is one that has an equal number of protons and electrons. Protons have a positive charge, while electrons have a negative charge, so an atom with an equal number of protons and electrons will have a net charge of zero.
Therefore, the correct answer is C: 2 protons, 2 electrons, and 1 neutron. This atom would have two positive charges (from the protons) and two negative charges (from the electrons), which cancel each other out, resulting in a neutral charge.