We know that one half-life of Phosphorus-32 is 14.3 hours. There are 24 hours in a day and 7 days in a week, so there are $24 \times 7 = 168$ hours in a week. Therefore, the number of half-lives in one week is $\frac{168}{14.3} \approx 11.7$ or approximately 12
Show more…