the half - life of a particular radioactive substance is 1 year. if you started with 40 grams of this…

the half - life of a particular radioactive substance is 1 year. if you started with 40 grams of this substance, how much of it would remain after 3 years? remaining amount = 40(1 - 0.50)^? remaining amount = i(1 - r)^t enter the number that belongs in the green box.
Answer
Answer:
3
Explanation:
Step1: Identify the formula variables
$I = 40$ (initial amount), $r=0.5$ (decay rate), $t$ is the number of half - lives.
Step2: Calculate the number of half - lives
The half - life is 1 year and the time passed is 3 years. So the number of half - lives $t=\frac{3}{1}=3$. This is the value that goes in the exponent position in the formula $Remaining\ Amount = I(1 - r)^t$.