What are CFCs?
CFCs are chlorofluorocarbons that contain only chlorine, fluorine and carbon.
What are some properties of CFCs?
Stable
Volatile
Non-flammable
Non-toxic
How is ozone formed naturally?
When an oxygen molecule is broken down into two free radicals by ultraviolet radiation.
The free radicals attack other oxygen molecules forming ozone.
What do CFCs in the upper ozone absorb?
UV radiation and split to form chlorine free radicals.
What do chlorine free radicals do to the ozone layer?
Catalyse the destruction of ozone - they destroy ozone molecules and are then regenerated to destroy more ozone.
What other compound can also break down ozone?
Nitrogen oxides
When were CFCs banned?
In the 1970s
What is one alternative to CFCs?
Hydrochlorofluorocarbons and hydrofluorocarbons are being used on a temporary basis until safer products are developed.