Answer:Phosphorus ahs an ocxidation number of 3. Phosphoric acid, H3PO3 has structure where there is one hydrogen (-H), two hydroxyl groups (-OH) and one oxgen (=O) attached to the central phosphorus P
Using the normal rules, H= +1, O = -2, OH = -1 and balancing out the "charges" we get P =+3
Explanation:
