Cl+O3 CI0+ O2 ·C|O+O C|+O2 One chlorine atom in the ozone layer can catalyze the transformation of 100,000 ozone molecules to oxygen molecules in one or two years• Cl + O3 ClO + O2 • ClO + O3 Cl + O2 • One chlorine atom in the ozone layer can catalyze the transformation of 100,000 ozone molecules to oxygen molecules in one or two years