Final answer:
To figure out isomer types, examine the molecular formulas and atom connections. Structural isomers differ in bond sequences, conformational isomers in rotations around bonds, and stereoisomers in 3D arrangements.
Step-by-step explanation:
To determine if molecules are structural isomers, conformational isomers, or not related, we need to look at their molecular formulas and the way their atoms are connected. Structural isomers have the same molecular formula but differ in the sequence in which atoms are bonded together, and changing from one structural isomer to another requires breaking covalent bonds. For example, compounds with different shapes, such as C4H10's isobutane and n-butane, are structural isomers. Conformational isomers, also known as conformers, are related by rotation around single sigma bonds and do not require breaking bonds to convert from one form to another. Lastly, stereoisomers have the same molecular formula and connectivity but differ in spatial arrangement. Within stereoisomers, we have subclasses like geometric isomers (cis-trans isomers), which differ in the arrangement of atoms around a planar double bond, and enantiomers, which are non-superimposable mirror images due to chiral centers, generally carbon atoms bonded to four different substituents. Identifying isomers often involves tracing the carbon backbone and assessing the connectivity and spatial arrangement of atoms.