Bonds in Ozone
- Ozone (O3) is a molecule composed of three oxygen atoms.
- Each oxygen atom is connected to the adjacent atoms by a double bond.
- The bonds in ozone have a considerable double bond character (option B is correct).
- This means that the oxygen atoms are not fully bonded to each other like in a single bond, but instead, they share electrons more like a double bond.
- The double bond character in ozone gives it unique properties and reactivity.

Physical Properties of Ozone
- Ozone is a pale blue gas (option C is correct) with a pungent odor.
- It is heavier than air and can be condensed into a dark blue liquid.
- At very low temperatures, ozone can solidify into a violet-black crystalline solid.
- Ozone is highly reactive and can decompose into oxygen molecules and atomic oxygen.

Ozone Conversion and Endothermicity
- Ozone can be converted back to oxygen through a process called ozone decomposition or Ozone-Oxygen Conversion.
- This process can occur spontaneously or can be induced by various factors such as heat, UV radiation, and certain catalysts.
- Conversion of ozone to oxygen is an exothermic reaction, meaning it releases heat.
- Conversely, the conversion of oxygen to ozone is an endothermic reaction, meaning it absorbs heat (option A is correct).
- The endothermic nature of ozone formation is due to the need to break the double bonds in oxygen molecules and create new bonds in ozone.

Depletion of Ozone Layer
- Nitric oxide (NO) and chlorofluorocarbons (CFCs) are responsible for the depletion of the ozone layer (option D is correct).
- Nitric oxide is primarily released into the atmosphere through human activities, such as combustion processes and industrial emissions.
- CFCs, commonly used as refrigerants and aerosol propellants, were found to be major contributors to ozone depletion.
- When released into the atmosphere, CFCs can reach the stratosphere, where they are broken down by UV radiation, releasing chlorine atoms.
- These chlorine atoms can then catalytically destroy ozone molecules, leading to the thinning of the ozone layer.

In summary, the correct statements regarding ozone are:
- The bonds in ozone have considerable double bond character (option B is correct).
- Ozone is a pale blue gas and dark blue liquid (option C is correct).
- Nitric oxide and freons (CFCs) are responsible for the depletion of the ozone layer (option D is correct).