The number of radioactive nuclei in a particular sample decreases to one-eighth of its original number in 9 days. What is the half-life of these nuclei?

Question

Quizplus · Accepted Answer

The half-life is the time it takes for half of the radioactive nuclei to decay. If the number decreases to one-eighth in 9 days, it means it has halved three times (since $2^3 = 8$). Therefore, the half-life is $9 \, \text{days} / 3 = 3$ days.

The Number of Radioactive Nuclei in a Particular Sample Decreases 9/89 / 89/8

The Number of Radioactive Nuclei in a Particular Sample Decreases $9 / 8$