you have 106,400 grams of a radioactive kind of selenium. how much will be left after 480 days if its half…

Explanation:

Step1: Calculate number of half - lives

The number of half - lives $n=\frac{480}{120}=4$.

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, $A_0 = 106400$ grams and $n = 4$. So $A=106400\times(\frac{1}{2})^4$.

Step3: Calculate the remaining amount

$(\frac{1}{2})^4=\frac{1}{16}$, and $A = 106400\times\frac{1}{16}=6650$ grams.

Answer:

6650