Final answer:
Tripling the separation between two point charges changes the potential energy by a factor of 1/9, as the potential energy between the charges is inversely proportional to the square of their separation distance.
Step-by-step explanation:
When you triple the separation between two point charges, the potential energy of the pair of charges is altered due to the inverse square nature of the electrostatic force governing their interaction.
According to Coulomb's Law, the force and therefore the potential energy between two point charges is inversely proportional to the square of the distance between them.
Hence, if the separation is tripled, the potential energy is changed by a factor of 1/32 or 1/9.
Therefore, tripling the separation between charges changes the potential energy by a factor of 1/9.