Carbon monoxide (CO) has a much smaller dipole moment than expected. This observation has puzzled chemists and led to much argument about the nature of the bonding in the molecule. There are three important resonance structures for the molecule. One of them has no formal charges; the other two are polarized in opposite directions. Write these resonance structures and analyze each one to see whether each atom has an octet around it; are the formal charges in accord with the relative electronegativities of C and O? Try to rationalize the small dipole moment of Co based on your answers.