d
Formal charges help in selection of the lowest energy structure from a number of possible Lewis

structures for a given species. Generally the lowest energy structure is the one with the smallest

formal charges on the atoms.

Formal charge on an atom \(=\) total no. of valence electrons - non-bonding electrons \(-\frac{1}{2} \times\) bonding

electrons.

For Lewis structure of \(\mathrm{SO}_{3}\)

Formal charge on S atom \(=6-0-\frac{1}{2} \times 12=0\)

Formal charge on three O atoms

\(=6-4-\frac{1}{2} \times 4=0\)