The ratio of parent to daughter isotopes in a radioactive decay process is 0.40.How many half-lives have elapsed since the material was 100% parent atoms? A)1-2 B)3 D)2-3

Question

The ratio of parent to daughter isotopes in a radioactive decay process is 0.40.How many half-lives have elapsed since the material was 100% parent atoms?
A)1-2
B)<1
C)>3
D)2-3

Quizplus · Accepted Answer

The ratio of parent to daughter isotopes is 0.40, which means that 60% of the parent atoms have decayed. Since each half-life reduces the number of parent atoms by half, it takes 2 half-lives to reduce the number of parent atoms to 40%.

The Ratio of Parent to Daughter Isotopes in a Radioactive