How is Ozone layer formed in the stratosphere? Name a chief chemical that causes its depletion.

Explanation

In stratosphere the free oxygen atoms combine with the molecular oxygen is presence of UV radiations to form ozone.
`O_(2)(g)overset(U.V.)(to)O(g)+O(g)`
`O(g)+O_(2)(g)overset(U.V.)(hArr)O_(3)(g)`
The chemical that causes its depletion is chlorofluorocarbon compounds or CFCs or fireons.