Question

The oxidation number of oxygen atom in $O_2^{2-}$ ion is

• A. - 3
• B. - 1
• C. - 5
• D. - 2.

Answer 1

Answer: (D)

Oxygen atom is monoatomic and oxidation number of an element in a monoatomic ion, is equal to the charge on the ion. i.e. -2.