Enantiomers are stereoisomers that are non-superimposable mirror images of each other. They have the same molecular formula and the same connectivity of atoms but differ in the spatial arrangement of those atoms in three-dimensional space. The key feature of enantiomers is that they have at least one chiral center, which is an atom usually carbon bonded to four different groups.The relationship between the two enantiomers of a molecule and their physical and chemical properties can be summarized as follows:1. Physical properties: Enantiomers have identical physical properties, such as melting points, boiling points, solubilities, and densities. This is because they have the same molecular formula and connectivity of atoms.2. Chemical properties: Enantiomers have the same chemical properties when they react with achiral reagents or in achiral environments. This means that they will undergo the same chemical reactions and produce the same products when reacting with achiral molecules.3. Optical activity: Enantiomers exhibit a unique property called optical activity, where they rotate plane-polarized light in opposite directions. One enantiomer will rotate the light clockwise dextrorotatory, denoted as + or d- , while the other will rotate it counterclockwise levorotatory, denoted as - or l- . The magnitude of the rotation is the same for both enantiomers but in opposite directions.4. Biological and pharmacological properties: Enantiomers can have different biological and pharmacological properties because the chiral centers in the molecules can interact differently with other chiral molecules, such as proteins and enzymes in living organisms. This can lead to differences in taste, smell, and drug activity. In some cases, one enantiomer may be therapeutically active, while the other may be inactive or even toxic.5. Reactions with chiral reagents or in chiral environments: When enantiomers react with chiral reagents or in chiral environments, they may exhibit different chemical properties and produce different products. This is because the chiral reagent or environment can differentiate between the two enantiomers and interact with them differently.In summary, enantiomers have identical physical properties and the same chemical properties in achiral environments, but they can exhibit different optical activities, biological/pharmacological properties, and chemical properties in chiral environments or when reacting with chiral reagents.