Which set of procedures and observations indicates a chemical change?
(1) ethanol is added to an empty beaker and the ethanol eventually disappears.
(2) a solid is gently heated in a crucible and the solid slowly turns to liquid.
(3) large crystals are crushed with a mortar and pestle and become powder.
(4) a cool, shiny metal is added to water in a beaker and rapid bubbling occurs.

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.