Final answer:
A meso compound is an achiral substance with multiple chiral centers that has a plane of symmetry, making it non-rotatory toward plane-polarized light. Compounds are made up of two or more elements chemically combined, and meso compounds are a specific case within molecular compounds.
Step-by-step explanation:
A meso compound is a unique type of achiral substance in the field of organic chemistry. It possesses multiple chiral centers, which are atoms in a molecule that are connected to four different groups or atoms, making the molecule asymmetrical. Despite having chiral centers, meso compounds exhibit an internal symmetry, often in the form of a plane of symmetry. This plane divides the molecule into two mirror-image halves, effectively cancelling out the compound's potential chirality. Consequently, meso compounds are superimposable on their mirror images and do not rotate plane-polarized light, a characteristic of chiral compounds. Examples of meso compounds can be demonstrated by considering molecules like tartaric acid, where specific isomers have this plane of symmetry despite having multiple chiral carbon atoms.
Understanding the concept of meso compounds also involves knowing what a compound is. A compound is a substance composed of two or more elements chemically combined in a fixed proportion. The atoms within a compound are bonded together using several types of chemical bonds, including polar covalent bonds, hydrogen bonds, non-polar covalent bonds, and ionic bonds. Molecules are the smallest units of compounds that retain the chemical identity of the compound. For example, water (H₂O) is a compound made of two hydrogen atoms bonded to one oxygen atom.