Using MO theory, predict which of the following species has the shortest bond length? (a) O (b) O (c) O (d) O Ans. (d) Sol. As we know, Bond length 1/bond order. In option A, Ohas bond order 2.5 In option B, Ohas bond order 1.5. In option C, O has bond order 1 In option D, O has bond order 3 Therefore, O has the shortest bond length.