`H_(3)PO_(3)` can be represented by structure (a) and (b) shown below. Can these two structures be taken as the canonical forms of the resonance hybrid representing `H_(3)PO_(3)` ?If not, give reasons for the same.

Explanation

The vasic requirement for the resonance is that the canonical structures must differ in the arrangement of the electron pairs nad not of the atoms. The structures (1) and (2) are not the cononical structures because in structure (1) phosphorus atom is linked wiht H (P-H bond) while in the other (2). it is linked wiht OH group (P-OH bond).