Final answer:
Constitutional isomers are compounds with the same molecular formula but different bonding sequences or structures, including skeletal isomers, positional isomers, and functional group isomers. Butane and isobutane are clear examples of constitutional isomers, having the formula C4H10 but differing in their structural arrangement. Other types of isomerism include geometric and stereoisomerization.
Step-by-step explanation:
Constitutional isomers are compounds that have the same molecular formula but differ in the sequence of bonds between the atoms. These can include various types of isomers like skeletal isomers, positional isomers, and functional group isomers. An example of constitutional isomers is the case of butane and isobutane, which share the molecular formula C4H10 but have different structures: a straight chain in butane and a branched chain in isobutane.
Isomerism is not limited to constitutional isomers; there are also stereoisomers. These include geometric isomers, like cis and trans forms of alkenes where the groups around a carbon-carbon double bond differ in arrangement, and enantiomers, which are nonsuperimposable mirror images of each other. Diastereomers are stereoisomers that are not enantiomers, such as cis- and trans-but-2-ene, due to their methyl groups' positioning around a double bond.