Final answer:
CFC's (chlorofluorocarbons) were the chemicals banned in the United States and many other countries for contributing to ozone depletion.
Step-by-step explanation:
The chemicals that were banned in the United States and many other countries for contributing to ozone depletion are CFC's (chlorofluorocarbons).
CFCs are stable compounds that release chlorine atoms when broken down by ultraviolet radiation.
These chlorine atoms then react with ozone molecules in the stratosphere, depleting the ozone layer and allowing harmful UV radiation to reach the Earth's surface.
As a result, the Montreal Protocol was established in 1987 to phase out the production and use of CFCs and other ozone-depleting substances.