When the transfer of electrons results in an ion larger than the original atom it?

When the transfer of electrons results in an ion larger than the original atom, it typically occurs when an atom gains electrons to become an anion. This increase in electron count leads to greater electron-electron repulsion within the electron cloud, causing the cloud to expand and the overall size of the ion to increase. Additionally, the effective nuclear charge experienced by the added electrons is lower, contributing to the increased ionic radius.