Question

Explain the reasons for ozone depletion in the stratosphere.

Hint:

Reducing the use of ozone-depleting substances like CFCs is essential for protecting the ozone layer.

Answer 1

Step 1: Ozone Layer and Its Importance.
The ozone layer is a region in the stratosphere that contains a high concentration of ozone (O₃). It is crucial for blocking harmful ultraviolet (UV) radiation from the sun.
Step 2: Causes of Ozone Depletion.
1. Chlorofluorocarbons (CFCs): CFCs are chemicals that, when released into the atmosphere, break down ozone molecules. They are commonly found in refrigerants, aerosols, and solvents. 2. Halons: These are chemicals used in fire extinguishers that also contribute to ozone depletion. 3. Nitrous Oxide: Emissions from fertilizers and vehicles can lead to the breakdown of ozone.
Step 3: How Ozone Is Depleted.
CFCs and other ozone-depleting substances reach the stratosphere, where UV radiation breaks them down. The chlorine atoms released by these chemicals react with ozone molecules, causing them to break apart, leading to a thinning of the ozone layer.
Step 4: Conclusion.
Ozone depletion is primarily caused by human-made chemicals like CFCs and halons, which break down ozone molecules in the stratosphere.
Final Answer: \[ \boxed{\text{Ozone depletion is caused by chemicals like CFCs and halons, which break down ozone molecules in the stratosphere.}} \]