Question

All the C-Obonds in carbonate ion are equal in length. Why?

Answer 1

Answer:

The carbonate ion is present as three resonating forms which differ only in the distribution of electrons. Neither of the three structures represent the actual molecule. In the carbonate ion, all CO bonds have equal bond length and bond strength with magnitude in between the CO single and CO double bond.

Answer 2

Answer:

Because it performs resonance so because of its resonating property all the bonds have partial double bond character and results into equal bond lengths. Carbonate ion is a symmetric, trigonal planar molecule. ... Instead, you can use resonance structures to understand this fact.