In chemistry isomerisation's the process by which one molecule's transformed into another molecule which has exactly the same atoms, but the atoms are rearranged for example A-B-C → B-A-C (these related molecules are known as isomers ). In some molecules and under some conditions, isomerisation occurs spontaneously. Many isomers are equal or roughly equal in bond energy, and so exist in roughly equal amounts, provided that they can interconvert relatively freely, that's the energy barrier… (More on Isomerisation)