Explain resonance with reference to carbonate ion.

Lewis structure of `CO_(3)^(2-)`

Explanation

(i) For the above structure, we can draw two additional lewis structures by moving the lone pairs from the other two oxygen atoms `O_(B) and O_(C)` and thus creating three similar structures in which the relative positive of the atoms are same.

Resonance structure of `CO_(3)^(2-)`
(ii) They only differ in the position of bonding and lone pair of electrons. Such structures are called resonance structures and this phenomenon is called resonance.
(iii) It is evident from the experimental results that all carbon-oxygen bonds in carbonate ion are equivalent. The actual structure of the molecule is said to be a resonance hybrid. an average of these 3 resonance forms. The following structure gives a qualitative idea about the correct structure of `CO_(3)^(2-)` (carbonate) ion.