Hello Student ,

First let us know about Resonance :

If a molecule of ion can be shown by two or more structures differing only in distribution of electrons but none of these structures truly explains all the properties of that molecule or ion , these structures are called resonating or canonical structures.

Characteristics :

1. It involves only displacement of electrons without disturbing nuclei.

2. All atoms in the molecule are in the same plane.

3. Total number of paired and unpaired electrons are same in any structure.

4. The canonical structures should have nearly equal energy.

5. The more stable a resonance structure is the more is its contribution to actual structure.

6. More the delocalisation more is the stability.

7. Stability increases with increase of covalent bonds.

8. The canonical structure on which N egative charge on more electronegative atom present is more stable.

9. Lesser the opposite charge separation more is the stability

10. The Resonance structures are hypothetical and individually don't represent any molecule.