A molecule is polar only if it contains polar bonds and
- A. has an even number of atoms
- B. contains at least one lone pair
- C. the individual bond dipoles do not cancel because of the molecular shape
- D. contains hydrogen
Explanation
Carbon dioxide has two strongly polar bonds but is linear, so the two dipoles point in opposite directions and cancel, leaving a non polar molecule with zero dipole moment. Water has similar bonds but is bent, so its dipoles add and the molecule is strongly polar. Shape therefore decides polarity just as much as electronegativity difference does.