the half - life of a radioactive kind of thallium is 5 minutes. how much will be left after 20 minutes, if…

Explanation:

Step1: Calculate number of half - lives

The half - life is 5 minutes and the time elapsed is 20 minutes. The number of half - lives $n=\frac{20}{5}=4$.

Step2: Use the radioactive decay formula

The formula for radioactive decay is $A = A_0\times(\frac{1}{2})^n$, where $A_0$ is the initial amount and $n$ is the number of half - lives. Here, $A_0 = 933392$ grams and $n = 4$. So $A=933392\times(\frac{1}{2})^4$.

Step3: Calculate the remaining amount

$(\frac{1}{2})^4=\frac{1}{16}$, and $A = 933392\times\frac{1}{16}=58337$ grams.

Answer:

58337