What type of structure do isomers have?

Isomers are compounds that share the same chemical formula but differ in their molecular structure or arrangement of atoms. This distinction means that isomers can have different physical and chemical properties despite containing the same number and types of atoms.

For instance, consider butane and isobutane; both have the chemical formula C4H10, but their structures differ significantly. In one structure, the four carbon atoms are arranged in a straight chain, while in the other, they branch out. These structural differences lead to varying boiling points, densities, and other properties.

Understanding isomers is essential in fields like organic chemistry because the arrangement of atoms can profoundly influence how a substance interacts with others in a chemical reaction. Thus, the correct answer emphasizes that isomers are distinguished primarily by their different arrangements of atoms while maintaining the same overall chemical formula.