Question

Which of the following condition is applied to resonating structure:
A. The contributing structure should have nearly the same energies
B. The contributing structure should be represented such that the like charges reside on the atom that is far apart
C. The more electropositive element should preferably have a positive charge and the more electronegative element should have a negative charge
D. The contributing structures must have the same number of unpaired electrons.

Answer 1

Hint: The phenomena of resonance is said to occur if, for a molecule, we can write two or more than two lewis structures which differ in the position of an electron, not in the relative position of atoms.

Complete step by step answer:
The various structures formed during the phenomena of resonance, which differ in the position of electrons and not in the relative position of atoms are called canonical structures or the resonance structures. There are various rules for writing the resonating structures are given below:
The various resonance structures should differ only in the position of electrons and not in the position of an atom.
All the resonating structures should have the same number of unpaired electrons and the resonating structures should have the nearly same energies.
In the resonating structure, the more electronegative atom has a negative charge and the more electropositive atom have a positive charge. And the structure should be represented that the like charge residing on the atom is far apart.

Thus we can say for writing the resonating structure all conditions given in the option are applicable.

Note: The contributing structures do not have a real existence and are imaginary and only resonance hybrids have a real existence. Resonance helps to explain the stability of a molecule by the concept of resonating energy and resonating energy is directly proportional to the stability of the molecule. Also, if there exists a larger number of resonating structures having nearly the same energy, larger will be the stability of the molecule.