instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
To determine the atomic weight of an element, you should add up protons and neutrons.
answer:
How do you determine the atomic weight of an element?


question:
Simple carbohydrates can be classified in terms of chain length.
answer:
Which carbohydrates can be classified in terms of chain length?


question:
Most fossils are found in sedimentary rocks because organisms can be preserved in sedimentary rock.
answer:

Why are most fossils found in sedimentary rocks?