Some chem students need help with homework problems similar to these later this week. and I want to make sure I've got the concepts down before I try to explain anything. This is for introductory chemistry. 1. Can a molecule have only nonpolar bonds and have a dipole? My first thought was no, that only molecules made of the same element have nonpolar bonds. As far as I can tell, this applies to diatomic molecules like F2 and not others like O3 after reading up on Wikipedia. Am I correct or is there an exception? 2. a) Would you expect CH4 or CF4 molecules to have dipoles? No b) Would you expect CH2F2 molecules to have dipoles? Yes c) Explain Since fluorine is more electronegative than hydrogen, the "side" of the CH2F2 molecule with the fluorines will be slightly more negative than the "side" with hydrogens, making the molecule have dipoles. 3. Why is the polarity of the covalent bonds in NaNO2 of little interest compared with that in a covalent molecule such as NO2? Not quite sure how to explain this one. The covalent bonds in NaNO2 are in the NO2- ion which has a -1 charge, while the NO2 molecule has no net charge. Is it that a net charge "overshadows" whatever polar covalent bonds may exist in something like NaNO2?