TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: Six many neutrons do 99% of carbon atoms have.

SOLUTION: How many neutrons do 99% of carbon atoms have?

PROBLEM: One of the properties of an air mass is that an air mass has similar temperature and moisture properties throughout it.

SOLUTION: Which of the following is true regarding the properties of an air mass?

PROBLEM: The rate of decay of carbon-14 does remains stable over time.

SOLUTION:
The rate of decay of carbon-14 does what over time?