Which statement is/are true about resonance ?

Options

A. It decreases the energy of system.
B. The hybridisation of atoms do not change due to resonance
C. Resonance hybrid is more stable than any resonating structure.
D. Resonanting structures can not be isolated at any temperature

Answer

To determine which statements about resonance are true, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement A: Resonance decreases the energy of the system.**
- **Analysis:** Resonance involves the delocalization of electrons across multiple structures, which leads to a decrease in the overall energy of the molecule. This decrease in energy results in increased stability of the molecule.
- **Conclusion:** This statement is **true**.

2. **Statement B: The hybridization of atoms does not change due to resonance.**
- **Analysis:** Resonance does not affect the hybridization of the atoms involved in the resonance structures. The skeletal structure remains the same, and only the distribution of electrons or charges changes.
- **Conclusion:** This statement is **true**.

3. **Statement C: The resonance hybrid is more stable than any resonating structure.**
- **Analysis:** The resonance hybrid represents a weighted average of all possible resonance structures. In the resonance hybrid, the charge is delocalized across the molecule, which increases stability compared to any individual resonance structure that may have localized charges.
- **Conclusion:** This statement is **true**.

4. **Statement D: Resonating structures cannot be isolated at any temperature.**
- **Analysis:** Resonance is a dynamic process, and the individual resonance structures are not real entities that can be isolated. They are hypothetical constructs that represent different ways of arranging electrons. Therefore, they cannot be isolated at any temperature.
- **Conclusion:** This statement is **true**.

### Final Conclusion:
All four statements regarding resonance are true.