Difference in bond energies

A) NO has a bond energy of 632 kJ/mol but the energy of each N—O bond in NO2 is 469 kJ/mol. Using Lewis dot diagrams, explain the difference in bond energies between the two molecules. Why are the two energies not equal equal? B) NO (g) + HO2 (g) to NO2 (g) + OH (g) Draw Lewis dot diagrams for HO2 and OH. Is either species a free radical? C) Knowing that the O—H bond energy is 463 kJ/mol and the O—O bond energy is 157 kJ/mol, calcuate whether the reaction in part b is endothermic or exothermic.