The ratio of radioactive parent to stable daughter atoms in a mineral is measured as 1:3. How many half- lives have elapsed since the mineral grain formed, assuming that only parent atoms were present when it crystallized?

Question

Quizplus · Accepted Answer

After one half-life, the ratio of parent to daughter atoms would be 1:1. After two half-lives, the parent atoms would have halved again, resulting in a 1:3 ratio of parent to daughter atoms, indicating that two half-lives have elapsed.

The Ratio of Radioactive Parent to Stable Daughter Atoms in a Mineral