Localized electrons are electrons that are associated with a specific atom or bond within a molecule, typically found in covalent bonds. These electrons tend to stay close to the nuclei of the atoms they are bound to, contributing to the stability of those bonds.
On the other hand, delocalized electrons are not confined to a single atom or bond. Instead, these electrons are spread out over several atoms, allowing them to move freely within a molecule or across multiple atoms. This is commonly observed in compounds like benzene, where the pi electrons are shared among all six carbon atoms, creating a more stable structure due to resonance.
In summary, the key difference lies in their distribution: localized electrons are fixed in place, while delocalized electrons are mobile and can participate in resonance structures. This distinction is crucial in understanding the stability and reactivity of various chemical compounds.