(N/A) According to experimental findings,all carbon-to-oxygen bonds in $CO_{3}^{2-}$ are equivalent.
Hence,it is inadequate to represent the $CO_{3}^{2-}$ ion by a single Lewis structure having two single bonds and one double bond.
Therefore,the carbonate ion is described as a resonance hybrid of the following three canonical structures:
[Image: $914-$s15]
Key aspects of resonance:
$1$. Resonance structures do not represent real molecules; they are hypothetical.
$2$. The actual structure of the molecule is a resonance hybrid of all canonical structures.
$3$. The energy of the resonance hybrid is lower than that of any individual canonical structure,providing stability.