Consider the following
\[
\mathrm{HF,\ H_2O,\ BeCl_2,\ CO_2,\ BF_3,\ NF_3,\ CCl_4,\ CHCl_3}
\]
The number of polar molecules is
Show Hint
A molecule is polar if it has
\[
\boxed{\text{a non-zero net dipole moment}.}
\]
Always consider both
\[
\boxed{\text{bond polarity and molecular geometry}.}
\]