Answer these questions based on the Periodic Table entry for sodium: 11
Na
22.991
What is the atomic mass?
What is the atomic number?
How many neutrons does sodium have?
What is the chemical symbol for sodium?
How many protons does sodium have?
How many electrons does it have in the n=2 orbit?

the correct answer is:

a. formation of precipitation

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.