Answer:
Hi, this is a super vague question, so its pretty confusing to answer. Could you please be a bit more specific?
If you are referring to chemistry, then how you tell "what is what" is by the molecular makeup of an element (Periodic table), and "how that..affects what", chemical reactions can occur between elements
Answer:
5=C, every action has an equal or opposite reaction,
6=B, since it has less air drag and more force exerted on it
7= You're correct
I don't know anything sorry for inconvenience but I will be used to make a system running with artificial intelligence