Final answer:
According to Coulomb's law, the potential energy of two oppositely charged particles decreases as they get closer together.
Step-by-step explanation:
According to Coulomb's law, the potential energy of two oppositely charged particles decreases as they get closer together. This is because the electrostatic force between the charged particles increases as the distance between them decreases. The potential energy is inversely proportional to the distance squared between the particles, so as the distance decreases, the potential energy decreases.