1.) List a few of the gases which lead to acid rain.
It comes from the gases sulfur dioxide and nitrogen oxides.

2.) What is the source of much of the acid rain producing gases in Pennsylvania?
Mostly it comes from the local power plants.

3.) Briefly explain how acid rain forms.
Acid rain forms when sulfur dioxide and nitrogen oxides in the sky mix with water to form sulfuric acid and nitric acid. These acids, mixed with rainwater, fall to Earth as acid rain, snow or fog.