If you have a 2700 gram sample of c-14 and 12 half-lives have passed how much of your original sample
remains. how much times has passed? _

A ( t )=0.659 gram of C-14

Explanation:

Mathematically exponential decay can be expressed as

where

A ( t )   - the amount left after t years;

A 0  - the initial quantity of the substance that will undergo decay;

t 1/2  - the half-life of the decaying quantity.

Calculation:

Given that

A 0  =2700 gram sample of C-14

t=time=12 times of half life of C-14

Required data:

A ( t )=?

Putting value in the attached equation we get

A ( t )=0.659 gram of C-14

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.