Question

If you have 100 g of a radioactive isotope that has a half-life of 15 years. How much of thesample will remain after 15 years

Answer 1

Using the formula for the amount of the remaining sample as,

$N=N_o(\frac{1}{2})^{\frac{t}{T}}$

Here t is the time for amount to be calculated, T is the half life time

Substituting the known values here,

$\begin{gathered} N=100\times(\frac{1}{2})^{\frac{15}{15}} \\ N=100\times(\frac{1}{2}) \\ N=50\text{ g} \end{gathered}$

Thus, the amount of the remaining sample is 50 g.