The net potential energy EN between two adjacent ions is sometimes represented by the expressionEN=−Cr+Dexp(−rrho)in which r is the interionic separation and C, D, and rho are constants whose values depend on the specific material.(a) Derive an expression for the bonding energy E0 in terms of the equilibrium interionic separation r0 and the constants D and rho using the following procedure:(i) Differentiate EN with respect to r, and set the resulting expression equal to zero.(ii) Solve for C in terms of D, rho, and r0.(iii) Determine the expression for E0 by substitution for C in the given equation.(b) Derive another expression for E0 in terms of r0, C, and rho using a procedure analogous to the one outlined in part(a).