<P> An isomer ( / ˈaɪsəmər / ; from Greek ἰσομερής , isomerès ; isos = `` equal '' , méros = `` part '' ) is a molecule with the same molecular formula as another molecule , but with a different chemical structure . Isomers contain the same number of atoms of each element , but have different arrangements of their atoms . Isomers do not necessarily share similar properties , unless they also have the same functional groups . There are two main forms of isomerism ( / ˈaɪsəməˌrɪzəm , aɪ ˈsɒ - / ) : structural isomerism ( or constitutional isomerism ) and stereoisomerism ( or spatial isomerism ) . </P>
<P> An isomer ( / ˈaɪsəmər / ; from Greek ἰσομερής , isomerès ; isos = `` equal '' , méros = `` part '' ) is a molecule with the same molecular formula as another molecule , but with a different chemical structure . Isomers contain the same number of atoms of each element , but have different arrangements of their atoms . Isomers do not necessarily share similar properties , unless they also have the same functional groups . There are two main forms of isomerism ( / ˈaɪsəməˌrɪzəm , aɪ ˈsɒ - / ) : structural isomerism ( or constitutional isomerism ) and stereoisomerism ( or spatial isomerism ) . </P>
species with different arrangements of atoms but having no structural differences
species with different arrangements of atoms but having no structural differences
isomer
isomer