\(\mathrm{NO}_{3}^{-}=32 \mathrm{e}^{-}\)

\(\begin{array}{l}\mathrm{CO}_{3}^{2-}=32 \mathrm{e}^{-} \\\mathrm{ClO}_{3}^{-}=42\mathrm{e}^{-}\end{array}\)

\(\mathrm{SO}_{3}^{-}=41 \mathrm{e}^{-}\)

Therefore, \(\mathrm{NO}_{3}^{-}\) and \(\mathrm{CO}_{3}^{2-}\) are isoelectronic The structures of both \(\mathrm{NO}_{3}^{-}\) and \(\mathrm{CO}_{3}^{2-}\) is trigonal planar. Therefore \(\mathrm{NO}_{3}^{-}\) and \(\mathrm{CO}_{3}^{2-}\) are isostructural also.