Final answer:
Chlorine atoms catalyze the decomposition of ozone through a cycle that allows a single chlorine atom to decompose multiple ozone molecules, initiated by the breakdown of CFCs in the stratosphere.
Step-by-step explanation:
Chlorine atoms play a vital role in catalyzing the decomposition of ozone in the Earth's stratosphere. This happens through a cycle where chlorine atoms react with ozone (O3) molecules to form chlorine monoxide (ClO) and molecular oxygen (O2). This process is crucial because it allows a single chlorine atom to destroy many ozone molecules over and over again. The overall reaction can be depicted as:
- Cl + O3 → ClO + O2
- ClO + O → Cl + O2
This catalytic cycle is initiated by Chlorofluorocarbons (CFCs) being broken down by ultraviolet light, releasing chlorine atoms. The stability of CFCs allows them to reach the stratosphere, where they can do the most damage. Fortunately, most of the atmospheric chlorine is found in inactive forms such as Cl2 and ClONO2, which do not participate in ozone depletion.