In the O2 molecule, what is the oxidation state of each oxygen atom?

In the O2 molecule, what is the oxidation state of each oxygen atom?

• A. -2
• B. -1
• C. 0
• D. +2

Answer: (C)

Oxidation states are assigned so that the sum equals the molecule’s overall charge. In a neutral diatomic molecule composed of identical atoms, there is no difference in electron ownership between the two atoms, so both have oxidation numbers of zero. Therefore, each oxygen atom in O2 has oxidation state 0. If you tried assigning -2 or -1 to each atom, the total would not match the neutral charge, and +2 would also contradict neutrality. The only consistent assignment is zero for each atom.

Oxidation states are assigned so that the sum equals the molecule’s overall charge. In a neutral diatomic molecule composed of identical atoms, there is no difference in electron ownership between the two atoms, so both have oxidation numbers of zero. Therefore, each oxygen atom in O2 has oxidation state 0. If you tried assigning -2 or -1 to each atom, the total would not match the neutral charge, and +2 would also contradict neutrality. The only consistent assignment is zero for each atom.