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

[Q]: Poles parts of the planet does solar energy have difficulty reaching.
[A]: What parts of the planet does solar energy have difficulty reaching?


[Q]: Sodium chloride is an odorless white solid that is harmless unless consumed in large quantities.
[A]: What is an odorless white solid that is harmless unless consumed in large quantities?


[Q]: Electrons in inner shells are called core electrons.
[A]:
Electrons in inner shells are called what?