The chemical mechanism by which chlorofluorocarbons CFCs react with ozone molecules in the atmosphere and lead to the depletion of the ozone layer involves a series of reactions. Here is a simplified explanation of the process:1. Photodissociation of CFCs: CFCs are relatively stable in the lower atmosphere but when they reach the stratosphere, they are exposed to high-energy ultraviolet UV radiation. This UV radiation causes the CFC molecules to break apart, or photodissociate, releasing highly reactive chlorine atoms Cl .CFC e.g., CFCl3 + UV radiation CFCl2 + Cl2. Reaction of chlorine atoms with ozone: The reactive chlorine atoms Cl released in the first step can then react with ozone O3 molecules, breaking them down into oxygen molecules O2 and chlorine monoxide ClO .Cl + O3 ClO + O23. Regeneration of chlorine atoms: The chlorine monoxide ClO produced in the second step can react with another ozone molecule, forming an oxygen molecule O2 and releasing the chlorine atom Cl back into the atmosphere.ClO + O3 Cl + 2 O24. Catalytic cycle: The chlorine atom Cl released in the third step can then react with more ozone molecules, repeating steps 2 and 3. This creates a catalytic cycle where a single chlorine atom can destroy thousands of ozone molecules before it is eventually removed from the stratosphere by other chemical reactions.The depletion of the ozone layer by CFCs has significant environmental effects, as the ozone layer plays a crucial role in protecting life on Earth from harmful UV radiation. Increased UV radiation can lead to higher rates of skin cancer, cataracts, and immune system suppression in humans, as well as negative effects on plant growth and marine ecosystems. This is why the production and use of CFCs have been phased out globally under the Montreal Protocol, an international treaty designed to protect the ozone layer.