2-pentene and 2-methylbutene exhibit structural isomerism, also known as constitutional isomerism. This type of isomerism occurs when molecules have the same molecular formula but different arrangements of atoms in their structures.Both 2-pentene and 2-methylbutene have the same molecular formula, C5H10, but their structures are different:1. 2-pentene has a carbon chain of five atoms with a double bond between the second and third carbons: CH2=CH-CH2-CH32. 2-methylbutene has a carbon chain of four atoms with a double bond between the second and third carbons, and a methyl group CH3 attached to the second carbon: CH3-C CH3 =CH-CH3These different arrangements of atoms in their structures result in different chemical and physical properties, making them isomers of each other.