Question

Which of the following is true regarding structural isomerism?

• A. The bonds between the molecules and the relative positions remain the same.
• B. Sometimes a new atom may be introduced, so the number of atoms might change.
• C. The functional group is always the same.
• D. None of these

Answer 1

The correct option is D None of these

Structural isomerism arises when molecules have the same molecular formula but the arrangement of their atoms is different.

Consider the following two molecules for example.



Here the molecular formula is $C_4{H}_{1}0$ in both cases but clearly, the structures are different.

So, it is easy to see that the bonds between molecules and the relative positions are always subject to change in structural isomerism. They remain the same in stereoisomers though.

The number of atoms always remains the same in all isomers and the functional group can vary which gives rise to functional isomerism