The blue curve in the plot here shows the potential energy of an ion A interacting with an ion B as a function of their separation distance. The red curve shows the interaction of ion A with a different ion (ion C) as a function of separation.

a. Do the charges on ions A and B have the same or different signs?

b. Do the charges on ions A and C have the same or different signs?

c. Is the magnitude of the charge on ion B greater than, equal to, or less than the magnitude of the charge on ion C?