PHYSICS · Multi-part · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
For an isolated ion pair A⁺ B⁻, the electrostatic potential energy is measured to be −2.4×10−19J at a separation distance of 300 pm.
Answer the following questions about hypothetical modifications to this ion pair.
(a) Calculate the new potential energy if the separation distance is reduced to 150 pm while all charges remain unchanged.
(b) Starting from the original ion pair, calculate the potential energy if instead the charge magnitude on each ion is doubled and the separation distance is left at 300 pm.
(c) Relative to the original situation, by what factor does the magnitude of the potential energy change in parts (a) and (b)? Comment briefly on which variable—charge or distance—has the greater effect when altered by the same numerical factor.