what are isomers

Isomers are molecules or polyatomic ions with identical molecular formula, meaning they have the same number of atoms of each element, but distinct arrangements of atoms in space/Chapters/Chapter_5%3A_Properties_of_Compounds/5.1%3A_Isomers). Isomerism refers to the existence or possibility of isomers. Isomers do not necessarily share similar chemical or physical properties. There are two main forms of isomerism: structural or constitutional isomerism, in which bonds between the atoms differ; and stereoisomerism or spatial isomerism, in which the bonds are the same but the relative positions of the atoms differ/Chapters/Chapter_5%3A_Properties_of_Compounds/5.1%3A_Isomers).