🔍 Key Concepts

• CFCs (chlorofluorocarbons) and what each letter stands for • How different halogens (like chlorine and fluorine) behave in the upper atmosphere • The specific role of catalytic reactions in breaking down ozone (O₃)

💭 Think About

• Look at the name CFC and match each letter to one of the elements in the choices to see which one is most associated with ozone depletion. • Think about which element can participate in a chain reaction that repeatedly destroys ozone molecules rather than being used up once. • Ask yourself: Which of these elements is specifically mentioned in discussions about the ozone hole over Antarctica?

✅ Before You Answer

• Confirm what each letter in CFC (chlorofluorocarbon) stands for and which of those is directly blamed for ozone destruction. • Verify which element forms a reactive radical in the stratosphere that can break apart ozone molecules many times over. • Make sure the element you choose is the one that is most famous in environmental regulations about banning or phasing out CFCs.