Which type of isomerism involves compounds with the same molecular formula but different connections among their atoms?

Structural isomerism occurs when two or more compounds share the same molecular formula but differ in the way their atoms are connected to each other. This type of isomerism covers a variety of different forms, including chain isomerism, position isomerism, and functional group isomerism. For example, butanol (C4H10O) can exist in several forms, such as n-butanol and isobutanol, which have the same molecular formula but different arrangements of their carbon skeleton.

This distinction in connection among atoms leads to different physical and chemical properties, which is why it's essential to understand structural isomerism in the study of chemistry. The other types of isomerism mentioned, such as geometric, stereoisomerism, and conformational isomerism, typically involve variations in the spatial arrangement of atoms rather than differences in how they are connected.