A tank contain 4liters of Oxygen. The gas temperature is 20oC and the measured pressure is 20 x 105 N/m2. Determine the mass of Oxygen. Given; Patm = 1x105, O = 16, 1dm3 = 1L, R = 8.314 N/mol/K)

explanation:

i did this but i forgot how to do it

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.