Q. What do you mean by Isomers?

Ans.

Compounds like butane and 2-methylpropane which have the same molecular formula but different molecular structures are called isomers. The following diagram illustrates two sets of isomers.

As the number of carbon atoms in a molecular formula increases, the number of possible structural isomers with that formula rapidly increases. The existence of isomers helps to account for the large number of possible organic compounds.