Help! Which change involves nitrogen being oxidized? the answer apparently is D, why? A. N2H4 → NH2 B. NO2 → N2O4 C. NO3 → N2O5 D. N2O → NO?

In A, the oxidation number of N in N₂H₄ is -2, while in NH₂ is also -2. There is no change in oxidation number of N, and thus N is neither being oxidized nor reduced.

In B, the oxidation number of N in NO₂ is +4, while in N₂O₄ is also +4. There is no change in oxidation number of N, and thus N is neither being oxidized nor reduced.

In C, the oxidation number of N in NO₃⁻ is +5, while in N₂O₅ is also +5. There is no change in oxidation number of N, and thus N is neither being oxidized nor reduced.

In D, the oxidation number of N in N₂O is +1, while in NO is +2. The oxidation number of N increases, and thus N is oxidized.

...... The answer: D. N₂O → NO

Because its a single Oxygen. Not 2 or more, but on .