Draw the bond-line formulas and IUPAC names for all constitutional isomers of C4H9Cl

Constitutional isomers are molecules with the same formula but different structure (and different name).

We start with a 4 carbon chain. We can put chlorine on carbon 1 or 2.

We then shorten the chain by one carbon and add that carbon to the middle of the molecule. Chlorine can go at the end carbon as well as middle.