Based on the oxidation number considerations, the oxidation numberof molecule will increase when they react with molecular oxygen. Itis because that oxygen got the tendency to lose 2 electron to formO2- , with oxidation number of -2. This is based on redox reaction. oxidation number of N in NO = +2 oxidation number of N in N2O = +1 The highest oxidation number of N is +5, they still can react withO oxidation number of S in SO2 = +4 oxidation number of S in SO3= +6 The highest oxidation number of S is +6, SO2 still canreact with O, but SO3 dont have the tendency to reactwith O more. oxidation number of P in P4O6= +3 The highest oxidation number of P is +5, P4O6still can react with O. So, the only one wont react with O is SO3 Solution Based on the oxidation number considerations, the oxidation numberof molecule will increase when they react with molecular oxygen. Itis because that oxygen got the tendency to lose 2 electron to formO2- , with oxidation number of -2. This is based on redox reaction. oxidation number of N in NO = +2 oxidation number of N in N2O = +1 The highest oxidation number of N is +5, they still can react withO oxidation number of S in SO2 = +4 oxidation number of S in SO3= +6 The highest oxidation number of S is +6, SO2 still canreact with O, but SO3 dont have the tendency to reactwith O more. oxidation number of P in P4O6= +3 The highest oxidation number of P is +5, P4O6still can react with O. So, the only one wont react with O is SO3.