1. Assign Oxidation Numbers to Oxygen:

* Oxygen usually has an oxidation number of -2, unless it's in a peroxide (like H₂O₂) or a superoxide.

2. Set Up an Equation:

* Let 'x' represent the oxidation number of nitrogen (N).

* Since there are two nitrogen atoms, we have 2x.

* The total oxidation number of the compound must equal zero.

* Our equation is: 2x + 5(-2) = 0

3. Solve for x:

* 2x - 10 = 0

* 2x = 10

* x = +5

Therefore, the oxidation number of nitrogen (N) in N₂O₅ is +5.