Final answer:
A single chlorine atom can destroy about 100,000 ozone molecules in the stratosphere, acting as a catalyst in a chain reaction. This process is initiated by the breakdown of CFCs due to ultraviolet radiation, with chlorine atoms persisting for up to two years.
Step-by-step explanation:
The chemistry of ozone depletion is a significant environmental concern. A single chlorine atom plays a catalytic role in the breakdown of ozone molecules in the stratosphere. This atom can initiate a reaction with an ozone molecule (O3) to form a chlorine monoxide molecule (ClO) and molecular oxygen (O2). The ClO can then react with a monatomic oxygen (O), releasing the chlorine atom to continue the cycle. It's been estimated that one chlorine atom can destroy around 100,000 ozone molecules before it is finally taken out of the cycle and transported back to the surface.
Chlorine atoms are released into the stratosphere by the breakdown of chlorofluorocarbons (CFCs), commonly found in the past in refrigerants, foams, and aerosols. The stability of CFCs allows them to reach the stratosphere, where they are broken down by ultraviolet radiation, releasing chlorine atoms that persist for up to two years, continuously depleting ozone.