Question

The half-life for P-32 is 14.3 days. What fraction of a sample of P-32 will be left after 42.9 days?

Answer 1

After 42.9 days, one-eighth (or 12.5%) of the original sample of P-32 will be left.

Step-by-step explanation:

The half-life is the time it takes for half of a sample of a radioactive substance to decay. In the case of P-32, with a half-life of 14.3 days, after 14.3 days, half of the sample will remain. After another 14.3 days (a total of 28.6 days), half of what was remaining will remain. So after 42.9 days, which is three half-lives, only one-eighth (or 12.5%) of the original sample will be left.

Answer 2

Answer: At one half-life (14.3 days) 230 mg of the P-32 would remain. at two half-lives (14.3 + 14.3 or 28.6 days) 115 mg of the P-32 would remain. at three half-lives (14.3 + 14.3 + 14.3 or 42.9 days) 57.5 mg of the P-32 would remain.

Explanation: