For a K+ –Cl– ion pair, attractive and repulsive energies EA and ER , respectively, depend on the distance between the ions r, according to For these expressions, energies are expressed in electron volts per K+ –Cl– pair, and r is the distance in nanometers. The net energy EN is just the sum of the two expressions above. (a) Superimpose on a single plot EN, ER, and EA versus r up to 1.0 nm. (b) On the basis of this plot, determine (i) the equilibrium spacing r0 between the K+ and Cl– ions,