Can a physical change, change what a substance is?

How do cfcs cause ozone depletion? how do cfcs cause ozone depletion? ultraviolet radiation breaks down cfcs, molecules containing chlorine. chlorine then breaks one oxygen atom away from ozone, leaving behind a paired oxygen molecule. ultraviolet radiation breaks down cfcs, molecules containing chlorine. chlorine then breaks two oxygen atoms away from ozone, leaving behind a paired oxygen molecule. ultraviolet radiation creates cfcs, molecules containing chlorine. chlorine then breaks two oxygen atoms away from ozone, leaving behind a paired oxygen molecule. ultraviolet radiation creates cfcs, molecules containing chlorine. chlorine then breaks one oxygen atom away from ozone, leaving behind a paired oxygen molecule.