$word_{count}$: 190

Bond order, bond length, and bond energy are interrelated: higher bond order = shorter bond length = higher bond energy (stronger bond). For carbon-carbon bonds: C-C (154 pm, 347 kJ/mol, order 1), C=C (134 pm, 614 kJ/mol, order 2), C triple C (120 pm, 839 kJ/mol, order 3). Note that energy does NOT scale linearly with order because pi bonds are weaker than sigma bonds. For the oxygen series: O2+ (112 pm, BO 2.5), O2 (121 pm, BO 2), O2- (126 pm, BO 1.5), $O2^{2-}$ (149 pm, BO 1). Resonance affects bond order: in $CO3^{2-}$, all C-O bonds have order 4/3 = 1.33, intermediate between single and double bonds. Bond energy exception: F-F $\frac{159 kJ}{mol}$ is weaker than Cl-Cl $\frac{242 kJ}{mol}$ due to lone pair-lone pair repulsion in the tiny F2 molecule. This is a common JEE trap. Bond polarity increases with electronegativity difference between atoms.