For example, the zero dipole of CO 2 implies that the two C=O bond dipole moments cancel so that the molecule must be linear. For H 2 O the O−H bond moments do not cancel because the molecule is bent. For ozone (O 3) which is also a bent molecule, the bond dipole moments are not zero even though the O−O bonds are between similar atoms. This agrees with the Lewis structures for the resonance forms of ozone which show a positive charge on the central oxygen atom.