The atomic symbol mc025-1.jpg represents potassium-40 (k-40), a radioactive isotope that has 19 protons and 21 neutrons. which atomic symbol could represent an isotope that results from the decay of k-40?

a) 40 ar
18

b) 40 k
18

c) 42 ca
20

d) 42 k
20

The correct option is A.

Explanation: For a radioactive isotope of potassium, which is having 19 protons and 21 neutrons, the decay processes are beta-decay and electron capture.

Potassium-40 undergoing decay processes:

From the two processes, the K-40 isotope forms by electron capture. So, the correct option is A.

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.