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.

[EX Q]: Question: What is the charge on a single electron known as? Answer: elementary charge
[EX A]: The charge on a single electron is and is known as the elementary charge.

[EX Q]: Question: What does rising air do when it reaches the top of the troposphere? Answer: cools
[EX A]: The rising air cools as it reaches the top of the troposphere. The air gets denser, so it sinks to the surface. The sinking, heavy air creates an area of high air pressure near the ground.

[EX Q]: Question: What two factors influence the pressure of fluids? Answer: depth and density
[EX A]:
Two factors influence the pressure of fluids. They are the depth of the fluid and its density.