In $\mathbf{P}_{4}$, the oxidation state of phosphorus is 0 because it is in its elemental form.
In $\mathrm{KH}_{2} \mathrm{PO}_{2}$, the oxidation state of phosphorus is +1. This is because oxygen is -2, hydrogen is +1, and potassium is +1. The sum of the
Show more…