What happens to CFCs when they rise to the stratosphere?

When chlorofluorocarbons (CFCs) reach the stratosphere, they are primarily exposed to ultraviolet (UV) radiation. This UV energy breaks down CFC molecules, releasing chlorine atoms into the atmosphere. These chlorine atoms are highly reactive and can interact with ozone (O3) molecules, leading to their destruction. The reaction results in a significant depletion of ozone in the stratosphere, which is concerning because ozone plays a crucial role in protecting the Earth's surface from harmful UV radiation.

In contrast, the other options do not accurately describe the fate of CFCs in the stratosphere. For instance, while it’s true that ozone absorbs some UV radiation, it does not completely absorb CFCs. CFCs do not create clouds in the stratosphere, nor do they condense and fall back to Earth; instead, they remain stable in the lower atmosphere but become reactive once they ascend to the stratosphere and are subjected to UV destruction. Therefore, the correct understanding of CFCs in relation to ozone depletion is their interaction with UV energy, leading to ozone destruction.