The expression sometimes represents the net potential energy (ENN) between two adjacent ions F ~ A = r C + D exp ( p r ) Where r is the interionic separation, and C , D , and r are constants whose values depend on the specific material. From above equation 1. Determine the attraction energy [2 Marks] 2. Determine the repulsion energy [2 Marks] 3. Derive the attraction force [6 Marks] 4. Derive the repulsion force [6 Marks].