What is the magnitude of the energy of a bond formed between a potassium (K+) cation and an iodide (I−) anion? The ionic radii of K+ and I−, are 152 pm and 206 pm, respectively. Assume the Born exponent n is 10. Please report your answer in joules.

http://chemistry.osu.edu/~woodward/ch754/ionicbonding.htm