$N_2$ is less reactive than $CN^{-}$ due to

Which of the following will have the maximum dipole moment?

Explain why $BeH_{2}$ molecule has a zero dipole moment although the $Be-H$ bonds are polar.

Which of the following molecules possesses a permanent dipole moment?

Which of the following molecules has a zero dipole moment?

If an $AB_3$ molecule (containing four atoms) has a dipole moment of zero and another has a non-zero dipole moment,what does this indicate about their shapes?