What are isomers?

Isomers are defined as compounds that have the same molecular formula but differ in their structural arrangement or the spatial orientations of their atoms. This can result in different physical and chemical properties, even though the molecules share the same composition of atoms.

For instance, consider butane (C4H10), which can exist as two isomers: n-butane, a straight-chain molecule, and isobutane, a branched molecule. These structural differences lead to variations in boiling points, melting points, and other characteristics, despite the fact that they contain the same number and type of atoms. The significance of isomerism is profound in chemistry and biology, where the specific arrangement of atoms can drastically impact a compound's reactivity and function.

Other definitions, such as those stating that isomers have different molecular formulas or identical properties, do not accurately describe isomers. Isomers can have diverse properties due to their structural differences, and they do indeed exist in various forms due to these structural distinctions. Hence, the definition emphasizing shared molecular formula alongside varying structures accurately captures the essence of isomers.