Question

"explain how the antarctic ozone hole is caused mainly by catalytic destruction of ozone by chlorine"

Answer 1

When humans improperly dispose of  equipment like refrigerators than have CFC and HCFCs, when they are subjected to UV light from the sun, they decompose to release Cl- radicals (CFCl3  CFCl2+ + Cl-). When the CL- are released into the atmosphere, they reach the stratosphere and react with the ozone. The Ozone is reduced from O3 to O2;

Cl + O3 -- ClO + O2

ClO + O - Cl + O2