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

Ex Input:
The properties of the alkali metals are similar to each other as expected for elements in the same family.

Ex Output:
The properties of the alkali metals are similar to each other as expected for elements in the same what?


Ex Input:
Most of the gray matter is on the surface of the brain, surrounding white matter.

Ex Output:
Most of the gray matter is on the surface of the brain, surrounding what other type of matter?


Ex Input:
You call a type of mixture that has the same composition throughout a solution.

Ex Output:

What do you call a type of mixture that has the same composition throughout?