what are geometric isomers

Geometric isomers, also known as cis-trans isomers or configurational isomers, are a type of stereoisomerism that describes certain arrangements of atoms within molecules/Fundamentals/Isomerism_in_Organic_Compounds/Geometric_Isomerism_in_Organic_Molecules). They occur when there is restricted rotation somewhere in a molecule, and the atoms making up the isomers are joined up in the same order but have a different spatial arrangement. Geometric isomers can only occur where there is restricted rotation about a bond, and they arise when there are two non-identical groups on each doubly bonded carbon atom/02%3A_Organic_Nomenclature_-_Unsaturated_Hydrocarbons/2.02%3A_Geometric_Isomers). The two isomers have the same number and types of atoms and bonds, but different spatial arrangements of the atoms. The isomer in which like ligands are adjacent to one another is called the cis isomer, while the isomer in which like ligands are opposite one another is called the trans isomer. Geometric isomers occur both in organic molecules and in inorganic coordination complexes.