Identify the correct answer.

Solution & Explanation

\textbf{Answer:} (C) Three canonical (resonance) forms can be drawn for $\mathrm{CO}{}_3{}^{2-}$ ion \textbf{Solution:} $\mathrm{BF}{}_3$ is trigonal planar and symmetric, so $\mu =0$ (A wrong). In $\mathrm{NH}{}_3$ the lone-pair moment and bond moments add (higher $\mu$) while in $\mathrm{NF}{}_3$ they oppose, so $\mu (\mathrm{NH}{}_3)>\mu (\mathrm{NF}{}_3)$ (B wrong). $\mathrm{CO}{}_3{}^{2-}$ has three equivalent canonical resonance forms (C correct). Ozone has two main resonance structures, not three (D wrong).