What are the two types of stereoisomers?

The correct answer identifies the two types of stereoisomers as enantiomers and diastereomers.

Stereoisomers are compounds that have the same molecular formula and connectivity of atoms but differ in the spatial arrangement of those atoms. Enantiomers are a specific type of stereoisomer that are non-superimposable mirror images of each other. This means that if one enantiomer is represented as a certain three-dimensional arrangement, its counterpart will have the same atoms arranged differently in three-dimensional space. Enantiomers typically exhibit distinct optical properties, rotating plane-polarized light in opposite directions.

Diastereomers, on the other hand, are stereoisomers that are not mirror images of each other. They have different configurations at one or more of the stereogenic centers but not at all of them. This leads them to have different physical and chemical properties, unlike enantiomers.

The distinction between these two categories is crucial in stereochemistry, affecting the reactivity and properties of the compounds involved. Understanding the differences between enantiomers and diastereomers helps in fields like pharmaceuticals, where the activity of a drug can depend on its stereochemistry.