|Class 11 Chemistry Chemical Bonding Structure||Resonance|
It is given by Heisenberg.
He took a molecule of ozone. Its structure was represented as:
According to the structure, it is clearly seen that it has one double bond and another single bond. So, obviously the bond lengths will be different. For double bond between oxygen atoms, the bond length is 121pm and for single bond it is 148pm.
But, the bond length was found experimentally to be same for both the bonds that is 128pm .This bond length lies in between the values of single and double bond lengths.
So, this proved that this structure is not able to explain and prove all properties .So ,it was assumed that ozone has two structures:
Resonance structures: Is defined as difference between actual bond energy and energy of most stable resonating structures.