Question

precipitation to reach earths surface. thus, acid deposition is the most accurate term, since the acid can come down through wet or dry means.
what ph level is used to classify precipitation as acid rain?
above 0
below 5.7
exactly 7
above 7

Explanation:

Normal, unpolluted rain has a pH around 5.7 due to natural carbon dioxide in the atmosphere. Precipitation is classified as acid rain when its pH falls below this threshold, as it indicates elevated acidic pollutants (like sulfur dioxide or nitrogen oxides) in the precipitation.

Answer:

below 5.7