Final answer:
Superposable molecules are identical to their mirror images; stereogenic centers create chirality; chiral molecules are not superposable on their mirror images; achiral molecules are superposable; enantiomers are non-superposable mirror images; diastereomers are not mirror images; a plane of symmetry indicates achirality; meso compounds are achiral despite having stereogenic centers.
Step-by-step explanation:
Superposable molecule: A molecule that can be placed on top of its mirror image and the atoms align perfectly is considered superposable. Often, superposable structures are not chiral.
Stereogenic center: It is an atom, typically carbon, that is attached to four different groups, imparting chirality to the molecule. These centers are essential for stereochemistry and can cause stereoisomerism.
Chiral molecule: A molecule that is not superposable on its mirror image and typically has at least one stereogenic center, making it chiral. This feature makes the molecule optically active, rotating plane-polarized light.
Achiral molecule: A molecule that is superposable on its mirror image. It lacks chirality, primarily due to the presence of a plane of symmetry or having identical groups attached to a central atom.
Enantiomers: Mirror-image isomers that are not superposable. Enantiomers are chiral molecules with opposite configurations at all stereogenic centers and have identical physical properties except for the direction in which they rotate plane-polarized light.
Diastereomers: Stereoisomers that are not mirror images of each other and are not superposable. They have different physical properties and are not necessarily optically active.
Plane of symmetry: A hypothetical plane that divides a molecule into two halves that are mirror images of each other. This feature is indicative of achiral molecules.
Meso compound: A unique type of achiral compound that contains multiple stereogenic centers and possesses a plane of symmetry cutting the molecule into two mirror-image halves.