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

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

[EX Q]: A concave lens is thicker at the edges than it is in the middle.
[EX A]: What type of lens is thicker at the edges than it is in the middle?

[EX Q]: Energy is stored in a chemical substance between atoms.
[EX A]:
Where is energy stored in a chemical substance?