Answer:
Chlorine and bromine
Step-by-step explanation: The chlorine and bromine acts as reactive gases and destroy the ozone present in the stratospheric ozone.
The ozone layer is present in the stratosphere to filter the harmful rays of the sun that is harmful for the people living on earth.
A chlorine or bromine molecule can destroy thousand of the ozone molecules before it leaves the stratosphere.
So, a single bromine or chlorine atom can affect the ozone layer.