Carbon-11 is used in medical imaging. The half-life of this radioisotope is 20.4 min. What percentage of a sample remains after 60.0 min?

Question

Quizplus · Accepted Answer

The half-life of Carbon-11 is 20.4 minutes. After 60 minutes, approximately 3 half-lives have passed (60/20.4 ≈ 2.94). The remaining percentage of the sample is calculated as (1/2)^3 ≈ 0.125, or 12.5%, which is closest to 13.0%.

Carbon-11 Is Used in Medical Imaging