What type of isomerism involves compounds with the same molecular formula but different connectivity of atoms?

The correct choice is structural isomerism because it specifically refers to isomers that share the same molecular formula but differ in the way the atoms are connected to one another. This type of isomerism emphasizes variations in the arrangement of the atoms within the molecule, leading to different structural frameworks.

For example, in structural isomerism, two compounds may have the formula C4H10; however, one might be a straight-chain alkane (butane), while the other could be a branched alkane (isobutane). These differences in connectivity result in distinct compounds with different chemical and physical properties.

Stereoisomerism, on the other hand, includes isomers that have identical connectivity but differ in the spatial arrangement of atoms. Geometric isomerism is a subtype of stereoisomerism that arises due to restricted rotation, typically around double bonds, leading to different spatial arrangements (cis and trans configurations). Optical isomerism involves compounds that are non-superimposable mirror images of each other, which is related to chirality but does not pertain to variations in atomic connectivity.

Thus, structural isomerism is the appropriate term for the scenario where compounds share a molecular formula while differing in how their atoms are connected.