instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
A(n) an ionic bond forms when the metal sodium gives up an electron to the nonmetal chlorine.
answer:
What forms when the metal sodium gives up an electron to the nonmetal chlorine?

question:
Air quality is a measure of pollutants in the air.
answer:
Air quality is a measure of what in the air?

question:
Ice wedging occurs because water expands.
answer:
Why does ice wedging occur?