Are chlorofluorocarbons (CFCs) considered highly stable or highly unstable?

Chlorofluorocarbons (CFCs) are actually considered highly stable compounds. Their stability in the lower atmosphere is a key reason why they were widely used in refrigeration, aerosol sprays, and other applications. This stability allows them to persist in the atmosphere for long periods without breaking down, which is why they can eventually travel to the stratosphere where they undergo photolysis due to ultraviolet radiation.

Once in the stratosphere, their stability becomes a concern because they release chlorine atoms that can significantly deplete the ozone layer. While they are stable in the atmosphere for extended periods, causing environmental issues, it is this very stability that leads to their long-range transport and subsequent impact.

In contrast, if a compound is labeled as highly unstable, it would break down quickly and would not endure in the atmosphere. Therefore, identifying CFCs as highly unstable would contradict what is understood about their behavior and environmental impact.