Answer:
Oxidation number per Nitrogen +5, oxidation number per Oxygen -2
Step-by-step explanation:
So we know that oxidation number of Oxygen is -2 so we have -2x5= -10 charge. This gives a total oxidation number charge of -10 for the five oxygen atoms in N2O5. To maintain electrical neutrality, as required for all compounds, the two nitrogen atoms must have a total oxidation charge of +10, so that each of the two nitrogen atoms has an oxidation number of +5