Definition: Given a scientific passage and an answer, generate a question for the given answer.
Input: Passage: Acid rain is rain that has a pH less than 5 ( Figure below ). Acidity is measured on the pH scale . Lower numbers are more acidic, and higher numbers are less acidic (also called more alkaline ). An acid has a pH of less than 7. The pH of normal rain is 5.6. It's slightly acidic because carbon dioxide in the air dissolves in rain. This forms carbonic acid, a weak acid. Answer: acid rain
Output:
What is the term for rain consisting of water with a ph below 5?