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

[EX Q]: Monatomic ions form when a single atom gains or loses electrons.
[EX A]: What form when a single atom gains or loses electrons?

[EX Q]: Some materials have negative heats of solution; the dissolution of one of these solutes in water is called?
[EX A]: Some materials have negative heats of solution; the dissolution of one of these solutes in water is called?

[EX Q]: A domain is the highest taxon in the classification of living things.
[EX A]:
What is the highest taxon in the classification of living things?