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

[Q]: Carbon atoms have six neutrons as well as six protons.
[A]: Carbon atoms have six neutrons as well as how many protons?


[Q]: Renewable energy sources emit fewer or no greenhouse gases.
[A]: What type energy sources emit fewer or no greenhouse gases?


[Q]: Producing light without heat is called luminescence.
[A]:
Producing light without heat is called what?