Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

[Q]: Mercury is the name of the smallest planet in our solar system, which is also nearest to the sun.
[A]: What is the name of the smallest planet in our solar system, which is also nearest to the sun?


[Q]: Learned behavior is adaptive because they are flexible, capable of changing if the environment changes.
[A]: What kind of behaviors are adaptive because they are flexible, capable of changing if the environment changes?


[Q]: The amount of energy required to begin a chemical reaction is known as the activation energy.
[A]:
What is the amount of energy required to begin a chemical reaction known as?