There are two different substances named trans-1,2- dimethylcyclopentane. What's the relationship between them?

The two different substances named trans-1,2-dimethylcyclopentane are isomers of each other. Isomers are compounds that have the same molecular formula but different structural arrangements or spatial orientations. In this case, the two substances have the same atoms (carbon, hydrogen) and the same number of each atom, but they differ in the arrangement of the atoms within the molecule. Specifically, the two substances differ in the spatial orientation of the two methyl (CH3) groups attached to the cyclopentane ring.