Organic Chemistry MCAT Practice Exam 2026 – The All-in-One Guide to Master Your Test Preparation!

The correct answer is structural isomerism, which refers to isomers that differ in the connectivity or arrangement of atoms within the molecule. This means that structural isomers have the same molecular formula but different structural formulas, resulting in variations in the way atoms are linked together in the compound.

Structural isomerism can be further categorized into various types, such as chain isomerism, position isomerism, and functional group isomerism. In each case, the atoms in the molecule are connected in a different fashion, leading to distinct chemical properties.

Stereoisomerism, on the other hand, involves isomers that have the same connectivity of atoms but differ in the spatial arrangement of those atoms in three-dimensional space. This includes cases such as enantiomers and diastereomers, which do not involve changes in the actual connectivity of the atoms. Geometric isomerism is a subtype of stereoisomerism where the spatial arrangement of substituents around a double bond or ring structure leads to distinct forms, such as cis and trans isomers. Enantiomerism specifically refers to a type of stereoisomerism where isomers are non-superimposable mirror images of each other, like left and right hands.

Thus,