# If a sample has 24 grams of I-131 (half life is: 8 days), how many grams of daughter nuclide would there be after 32 days?

Feb 5, 2016

1/16

#### Explanation:

$\frac{32}{8} \equiv 4$
So the I-131 will endure for 4 times its half live.
${\left(\frac{1}{2}\right)}^{4} = \frac{1}{16}$

By words:
So after 8 days, will be reduced into half.
after 16 days into a quarter
after 24 days into an eight
after 32 days into 1/16.