Question

what do the polar - shaped molecules have in common that the nonpolar ones do not?

Explanation:

Polar - shaped molecules have a net dipole moment. This means that there is an uneven distribution of electron density within the molecule, resulting in a partial positive charge on one end and a partial negative charge on the other end. Non - polar molecules, on the other hand, have a symmetrical distribution of electron density, so there is no net dipole moment.

Answer:

Polar - shaped molecules have a net dipole moment (an uneven distribution of electron density leading to partial charges) which non - polar molecules do not have.