\[
\begin{array}{|c|c|c|c|}
\hline \text{cation} & \text{anion} & \text{empirical formula} & \text{name of compound} \\
\hline \mathrm{Pb}^{2+} & \mathrm{I}^{-} & \boxed{\mathrm{PbI}_2} & \boxed{\text{Lead (II) iodide}} \\
\hline \mathrm{Pb}^{4+} & \mathrm{I}^{-} & \boxed{\mathrm{PbI}_4} & \boxed{\text{Lead (IV) iodide}} \\
\hline \mathrm{K}^{+} & \mathrm{I}^{-} & \boxed{\mathrm{KI}} & \boxed{\text{Potassium iodide}} \\
\hline \mathrm{Ca}^{2+} & \mathrm{I}^{-} & \boxed{\mathrm{CaI}_2} & \boxed{\text{Calcium iodide}} \\
\hline
\end{array}
\]