Structural isomerismStereoisomerismGeometrical isomerism (cis–transE/Z)Optical isomerismChirality and elements of symmetryChiral centers (asymmetric carbon atoms)Achiral vs. chiral moleculesPlane of symmetrycenter of symmetryaxis of symmetryOptical activityEnantiomers and diastereomersD-L and R-S nomenclature (Cahn-Ingold-Prelog rules)Properties of enantiomersRacemic mixturesMethods of resolutionMeso compoundsFischer projectionsNewman and Sawhorse projectionsStereoselectivity and stereospecificityNumber of possible stereoisomersAxial chirality (allenesbiphenyls)Conformational isomerism (ethanebutanecyclohexane conformations)Energy profile diagramsConfigurational vs. conformational isomerism