$H_3PO_3$ can be represented by structures $(1)$ and $(2)$ shown below. Can these two structures be taken as the canonical forms of the resonance hybrid representing $H_3PO_3$? If not,give reasons for the same.

(N/A) No,these two structures cannot be taken as the canonical forms of the resonance hybrid.
In resonance,the positions of the atomic nuclei must remain the same in all canonical structures.
In the given structures $(1)$ and $(2)$,the position of the hydrogen atom $(H)$ is different (attached to different oxygen atoms),which implies a change in the position of the nuclei.
Therefore,these are not resonance structures but are different isomers (tautomers) of $H_3PO_3$.