What is Chain - Cycle isomerism, Metamerism, Tautomerism, Stero isomerism, Chirality, Achiral, Asymmetric center and chiral chain, stereogenic center, Geometrical isomerism, optical isomerism,

Here are the definitions for those terms:

• Chain-Cycle isomerism: Isomers that have the same molecular formula but one is an open-chain compound and the other is a cyclic compound. For example, but-1-ene (CH₂=CH-CH₂-CH₃) and cyclobutane (a four-membered ring) are chain-cycle isomers, both C₄H₈.

• Metamerism: A type of structural isomerism where isomers have the same molecular formula and the same functional group, but differ in the arrangement of alkyl groups around the functional group (often involving a heteroatom like O, S, or N). For example, diethyl ether (CH₃CH₂-O-CH₂CH₃) and methyl propyl ether (CH₃-O-CH₂CH₂CH₃) are metamers.

• Tautomerism: A special type of functional group isomerism where two isomers (tautomers) exist in dynamic equilibrium and can interconvert rapidly by the migration of a proton and a double bond. A common example is keto-enol tautomerism.

• Stereoisomerism: Isomers that have the same molecular formula and the same connectivity of atoms, but differ in the three-dimensional spatial arrangement of their atoms.

• Chirality: The property of an object (like a molecule) that is non-superimposable on its mirror image. A chiral molecule is often described as having "handedness."

• Achiral: The property of an object (or molecule) that is superimposable on its mirror image. Achiral objects lack handedness.

• Asymmetric center: A carbon atom that is bonded to four different groups. This is also commonly called a chiral center and is a common source of molecular chirality.

• Chiral chain: A molecule with a chain structure that exhibits chirality, meaning the entire chain molecule is non-superimposable on its mirror image. This often arises from the presence of one or more asymmetric centers within the chain.

• Stereogenic center: Any atom or group of atoms within a molecule where the interchange of two groups attached to it leads to a stereoisomer. This includes chiral centers and the carbons involved in a cis-trans double bond.

• Geometrical isomerism: A type of stereoisomerism where isomers differ in the spatial arrangement of atoms or groups around a rigid structure, such as a carbon-carbon double bond or a ring. These are often referred to as cis-trans isomers.

• Optical isomerism: A type of stereoisomerism where the isomers (enantiomers) are non-superimposable mirror images of each other and have the ability to rotate plane-polarized light in opposite directions.