Among the given items,Chlorofluorocarbons (CFCs) is responsible for formation of ‘Ozone Holes’ in the stratosphere. Ultraviolet radiation in the stratosphere causes the CFCs molecules to dissociate, producing chlorine atoms and radicals (i.e., chlorodifluoromethyl radical; free radicals are species that containone or more unpaired electrons). CCl2F2
sunlight
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Cl+CClF2 dichlorodifluoromethane Chlorine atom Chlorodifluoromethyl radical
The chlorine atoms then react with ozone, initiating a process whereby a single chlorine atom can cause the conversion of thousands of ozone molecules to oxygen. Cl+O3–––––––>ClO+O2 Chlorine atom ozone Chlorine monoxide oxygen
'Ozone Hole’ is seasonal thinning of the ozone layer of the earth's atmosphere above Antarctica, so allowing abnormal amounts of ultraviolet light to reach the earth's surface.