Unformatted text preview: t cannot be
described adequately by a single structure. Resonance structures have the same sigma bonds
but differ in the arrangement of the pi bonds. The actual bonding is a mixture of the various
possible arrangements, and will have a lower energy than any of the individual forms. The
phenomenon is called delocalization because the valence electrons provided by individual
atoms are no longer held in the vicinity of that atom, but are mobile and shared by a number
of atoms. It is this spreading out of the electrons that gives the structure its lower potential
energy than it would have if double and single bonds were arranged in such a way that
orbital overlap could not take place. Thus, delocalization stabilizes a structure.
Bonds have electron distribution with axial symmetry around the axis joining the two
nuclei (from combination of two s orbitals or an s and a p or hybridized orbitals); π bonds
result from the sideways overlap of parallel p orbitals with...
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