You're asking about the oxidation state of nitrogen (N) in the ammonium ion (NH₄⁺). Here's how to determine it:

* Hydrogen's Oxidation State: Hydrogen typically has an oxidation state of +1, except in metal hydrides where it's -1.

* Overall Charge: The ammonium ion has a +1 charge.

* Calculating Nitrogen's Oxidation State:

* Let the oxidation state of nitrogen be "x".

* The total oxidation state of the four hydrogen atoms is +4 (4 x +1 = +4).

* To balance the +1 charge of the ammonium ion, the oxidation state of nitrogen must be -3.

* x + 4 = +1

* x = -3

Therefore, the oxidation state of nitrogen in NH₄⁺ is -3.