Compounds with same molecular formula but differing in their structures are said to be structural isomers. What type of structural isomerism is shown by

The above two compounds exhibit chain isomerism. Isomers are compounds that have same molecular formula but different structures. In the above structures, both have the same functional group (thioether / sulphide), but there is difference in the arrangement of atoms in the main chain. The first one is linear( propylmethylsulphide) , while the second one(isopropylmethylsulphide) is branched, i.e., there is difference in the chains attached to –S-. hence they are exhibiting chain isomerism.