Answer: 3
Explanation: Formula used for calculating the hybrid orbitals:
\(CO_3^{2-}:\)
\(:{\text{Number of electrons}} =\frac{1}{2}[V+N-C+A]\)
where, V = number of valence electrons present in central atom i.e. carbon = 4
N = number of monovalent atoms bonded to central atom=0
C = charge of cation = 0
A = charge of anion = -2
\({\text{Number of electrons}} =\frac{1}{2}[4+0-0+2]=3\)
The number of electrons is 3 that means the hybridization will be \(sp^2\) and the electronic geometry of the molecule will be trigonal planar which will be formed by three \(sp^2\) hybrid orbitals.
