To determine which pairs of ions are isoelectronic and isostructural, we need to analyze each option.$\\$Isoelectronic species have the same number of electrons.$\\$Isostructural species have the same shape or geometry.$\\$Let's evaluate each option:$\\$Option 1: $$ClO$_3^-$ and CO$_3^{2-} \\$• ClO$_3^-:$Chlorine (Cl) has 17 electrons, and each oxygen (O) has 8 electrons.$\\$ Total electrons = 17 + 3(8) + 1 (for the negative charge) = 34 electrons.$\\$• CO$_3^{2-}:$Carbon (C) has 6 electrons, and each oxygen (O) has 8 electrons.$\\$ Total electrons = 6 + 3(8) + 2 (for the 2- charge) = 32 electrons.$\\$These ions are not isoelectronic.$\\$Option 2: $$SO$_3^{2-}$ and NO$_3^- \\$• SO$_3^{2-}:$Sulfur (S) has 16 electrons, and each oxygen (O) has 8 electrons.$\\$ Total electrons = 16 + 3(8) + 2 (for the 2- charge) = 42 electrons.$\\$• NO$_3^-:$Nitrogen (N) has 7 electrons, and each oxygen (O) has 8 electrons.$\\$ Total electrons = 7 + 3(8) + 1 (for the negative charge) = 32 electrons.$\\$These ions are not isoelectronic.$\\$Option 3: $$ClO$_3^-$ and SO$_3^{2-} \\$• ClO$_3^-:$Total electrons = 34 electrons (as calculated above).$\\$• SO$_3^{2-}:$Total electrons = 42 electrons (as calculated above).$\\$These ions are not isoelectronic.$\\$Option 4: $$CO$_3^{2-}$ and SO$_3^{2-} \\$• CO$_3^{2-}:$Total electrons = 32 electrons (as calculated above).$\\$• SO$_3^{2-}:$Total electrons = 42 electrons (as calculated above).$\\$These ions are not isoelectronic.$\\$Upon reviewing the options, it seems there was an error in the provided correct option.$\\$Let's re-evaluate:$\\$The correct pair should be isoelectronic and isostructural.$\\$Re-evaluating:$\\$Option 3: $$ClO$_3^-$ and SO$_3^{2-}$ are not isoelectronic.$\\$The correct answer should be:$\\$None of the given pairs are both isoelectronic and isostructural.$\\$Please verify the correct option as the provided answer seems incorrect.