In chemistry, isomers are compounds with the same molecular formula but different structural formulas. The word is derived from the Greek ισομερης, isomerès; isos = "equal", méros = "part". There are many different classes of isomers, like stereoisomers, enantiomers, geometrical isomers, et cetera (see chart below). Isomers don't necessarily share similar properties, unless they also have the same functional groups. There are two main forms of i… (More on Isomers)