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

[EX Q]: Six many neutrons do 99% of carbon atoms have.
[EX A]: How many neutrons do 99% of carbon atoms have?

[EX Q]: Matter that mechanical wave energy can only travel through is medium.
[EX A]: What is the name of matter that mechanical wave energy can only travel through?

[EX Q]: In humans, a zygote has 46 chromosomes.
[EX A]:
In humans, a zygote has how many chromosomes?