\begin{tabular}{|c|c|c|c|} \hline \multicolumn{2}{|c|}{ some ionic compounds } \\ \hline cation & anion & empirical formula & name of compound \\ \hline Pb4+ & PO43 & & \\ \hline Na+ & BrO2 & & \\ \hline K+ & ClO4 & & \\ \hline Sn2+ & NO3 & & \\ \hline \end{tabular}