\[
\begin{array}{c|l|c}
\hline \text{molecule or} & \text{polar or} & \text{atom closest to} \\
\text{polyatomic ion} & \text{nonpolar?} & \text{negative side} \\
\hline \mathrm{F}_{2} & \text{nonpolar} & \boxed{\text{None}} \\
\hline \mathrm{CS}_{2} & \text{nonpolar} & \boxed{\text{None}} \\
\hline \mathrm{CH}_{3} \mathrm{~F} & \text{polar} & \boxed{\mathrm{F}} \\
\hline
\end{array}
\]