It’s when water and oxygen in normal precipitation mix with compounds such as sulfur dioxide and nitrogen oxides in the atmosphere. The chemical reaction turns clean rain -- which is naturally acidi The acids produced in the acid rain can fall near the original source of pollution. Winds can also blow contaminated dust in the atmosphere even farther and it can fall there, blanketing more areas.c -- dangerously so. Scientists measure acidity on the pH scale from 0 to 14. Water with a pH of 7 is neutral. Battery acid is most acidic with a pH of 0. Liquid drain cleaner falls on the other end of the scale, called basic, with a pH of 14. Acid rain comes in two forms: Wet. The compounds turn into acids in the atmosphere and fall down as rain, sleet, snow, fog, or hail. Dry. This is when compounds produce acids and float down to the ground as dust and gas. Future rains can...