Butane and 2-methylpropane are constitutional isomers. This means that they have the same molecular formula but different connectivity of atoms in their structures.Here are the structures for each of the isomers:Butane:H H H H| | | |H-C-C-C-C-H| | | |H H H H2-methylpropane also known as isobutane :H H H| | |H-C-C-C-H| | |H H-C-H | HBoth butane and 2-methylpropane have the molecular formula C4H10, but their structures are different. Butane has a straight chain of four carbon atoms, while 2-methylpropane has a branched structure with three carbon atoms in the main chain and one methyl group CH3 attached to the second carbon atom.The difference in their structures leads to differences in their physical properties. For example, the boiling points of these two isomers are different. Butane has a boiling point of -0.5C 31.1F , while 2-methylpropane has a boiling point of -11.7C 10.9F . The reason for this difference is that butane has a more extended structure, which allows for stronger London dispersion forces a type of van der Waals forces between the molecules. In contrast, 2-methylpropane has a more compact structure, which reduces the strength of the London dispersion forces between the molecules, leading to a lower boiling point.In summary, butane and 2-methylpropane are constitutional isomers with different structures and physical properties due to the differences in their molecular connectivity and the resulting intermolecular forces.