Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.
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Question: Question: What are the highest clouds in the atmosphere? Answer: noctilucent clouds

Answer: Noctilucent clouds are the highest clouds in the atmosphere.

Question: Question: Where do radio waves lie on the electromagnetic spectrum? Answer: far left

Answer: Courtesy of NASA. Radio waves lie at the far left of the electromagnetic spectrum . Public Domain.

Question: Question: What is the ph level of neutral, pure water? Answer: seven

Answer:
The ion concentration of neutral, pure water gives water a pH of 7 and sets the standard for defining acids and bases. Acids have a pH lower than 7, and bases have a pH higher than 7.