Formation of O2 from O3
Formation of O2 from O3 is an exothermic process. This means that energy is released during the reaction.

Explanation:
- When ozone (O3) molecules decompose into oxygen (O2) molecules, the bond energy of the O-O bond in O3 is greater than the bond energy of the O=O bond in O2.
- As a result, when O3 molecules break apart to form O2 molecules, energy is released in the form of heat. This release of energy makes the reaction exothermic.
- The reaction can be represented as follows:
2 O3 → 3 O2 + heat
- The energy released during this reaction is due to the formation of more stable O2 molecules from less stable O3 molecules.
- This exothermic reaction is important in the upper atmosphere, where ozone depletion occurs. The breakdown of ozone into oxygen helps to regulate the ozone layer and protect the Earth from harmful UV radiation.
In conclusion, the formation of O2 from O3 is an exothermic process because it releases energy in the form of heat.

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