Why are the three most abundant elements (hydrogen, helium, oxygen) in the universe and the five most abundant elements(Oxygen, Silicon, Aluminum, Iron, and Calcium) on Earth different? What happened as the Earth formed, or since that time, to change the composition of the Earth?

it's c. elements are placed in rows based on how may valencies electrons have.

2b2t

explanation:

2b2t

b. is the answer hoped i        

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.