Remember when your mother used to scold you for opening your mouth to the deadly sky as it was pouring? "It's acid rain," she'd say. Envisioning raindrops burning through my gums, jaw, and skin, I always followed my mother's advice. But the last I ever heard about acid rain was in the "˜90s. So where did it go? And what was acid rain, anyway?
Technically speaking, acid rain is rain with, well, acid! Anything with a pH level of below 7 is considered acidic. While even "clean" rain has a pH of 5.5... READ ON