Write the structural formulae of all the isomers of hexane.

There are 5 isomers of hexane. They are hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, and 2,3-dimethylbutane. They are known as constitutional isomers because they each contain exactly the same number and type of atoms. In this case, six carbons and 14 hydrogens and no other atoms.