- AFluorine
- BCarbon
- Chlorine
- DHydrogen
Correct answer
Chlorine
Why
Chlorine atoms released from CFCs and HCFCs destroy ozone molecules. One chlorine atom can destroy thousands of ozone molecules.
The concept behind this question
Ozone depletion potential (ODP) measures how much damage a compound does to stratospheric ozone, and chlorine is the culprit. CFCs carry the most chlorine and the highest ODP, HCFCs carry less and are transitional, and HFCs contain no chlorine and have an ODP of zero. Zero ODP is not the same as harmless — many HFCs have high global warming potential (GWP), which is what the more recent phase-down addresses.
More questions on this topic
- Which of the following refrigerants has the highest Ozone Depleting Potential (ODP)?
- Where is the ozone layer located?
- What does the ozone layer protect us from?
- What type of refrigerant is R-22?
- What happens to CFCs and HCFCs when they reach the stratosphere?
- How many ozone molecules can one chlorine atom destroy?
Exam-style practice question. Not an official EPA exam question.