What is here?

Isomers are molecules with the same molecular formula but different arrangements of atoms. There are different types of isomerism, shown by the flow chart below.

Use the flowchart or the links in the text to find out more.

Each page includes molecule models.

Functional group isomers of C2H6O

Structural isomerism

Structural isomerism occurs when two or more organic compounds have the same molecular formula, but their atoms are arranged in different orders. These differences tend to give the molecules different chemical and physical properties. There are three types of structural isomerism that you need to be aware of at school:


Stereoisomerism occurs when the atoms are joined in the same order, but they can have different arrangements in space. This includes: