O3<H2O2<O2
O2<H2O2<O3
H2O2<O2<O3
O2<O3<H2O2
Bond length is inversely proportional to bond strength and bond strength is directly proportional to bond dissociation energy and H2O2 has a single bond, O3 has a partial double bond because of resonance, and O2 has a double bond so the correct order is O2<O3<H2O2. Bond length of O−O in O2=1.21Å, O3=1.273Å and H2O2=1.49Å