Ozone is a molecule containing three atoms of oxygen (O3)/ a highly poisonous gas present in the upper layer of the atmosphere.
Formation of ozone - The UV radiations split some molecular oxygen (O2) apart into free oxygen atoms (O + O). These atoms then combine with molecular oxygen to form ozone.
Or
O2 + uv → O + O
O + O → O3(Ozone)
Effect - Ozone layer shields the surface of the earth from damaging UV radiations of the sun.
