Resonance forms

Definition

Resonance forms are different Lewis structures for the same molecule that depict the delocalization of electrons within the molecule. These forms help to illustrate how electrons can be distributed across various atoms while maintaining the overall connectivity.

5 Must Know Facts For Your Next Test

1. Resonance forms do not represent different molecules; they are different depictions of the same molecule.
2. The actual structure of a molecule is a hybrid of its resonance forms, known as the resonance hybrid.
3. Resonance improves the stability of a molecule by allowing electron delocalization.
4. Formal charges can be used to determine the most significant resonance form, preferring structures with formal charges closest to zero.
5. All resonance forms must have the same arrangement of atoms; only electron positions can differ.

Review Questions

• What is meant by the term 'resonance hybrid'?
• How do formal charges help in determining the most significant resonance form?
• Why do resonance forms contribute to molecular stability?

Related terms

Formal Charge:

A theoretical charge assigned to an atom in a molecule, calculated based on valence electrons minus non-bonding electrons and half of bonding electrons.

Lewis Structure:

A diagrammatic representation showing how valence electrons are arranged among atoms in a molecule.

Delocalization: The spreading of electron density over several adjacent atoms rather than being localized between two atoms.