Question

The half-life of 131I is 8.021 days. What fraction of a sample of 131I remains after 24.063 days?

1/2
1/4
1/8
1/16
Please help. Thank you

Answer 1

How many half days is that?
24.063/8.021 = 3

(1/2)(1/2)(1/2) = 1/8

Answer 2

By the way, I did that simple calculation rather than going through the exponential decay routine because the suggested answers were such simple fractions that I guessed we would have a simple number of half days.

Answer 3

Thanks

Answer 4

You are welcome :)