What are "representative elements"? A. Elements in the short columns of the periodic table
B. Elements in the same rowof the periodic table
C. Elements that share the same properties on the periodic table
D. Elements in the tall columns of the periodic table

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)

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.