While these molecules are related, they are actually pairs of constitutional isomers, not resonance structures. One way to avoid making these types of mistakes is to try to interconvert the structures usingcurved arrows. There are onlythree legal arrow-pushing movesfor drawing resonance structures. ...
We could also use the line to depict the carbon skeleton, while drawing in the bonds to hydrogen as dashes and wedges to depict them in 3D. It takes some practice to do this properly to make sure that the carbons get properly represented as tetrahedra. Finally there’s the projections – ...