the half - life of a particular radioactive substance is 3 years. if you started with 60 grams of this…

the half - life of a particular radioactive substance is 3 years. if you started with 60 grams of this substance, how much of it would remain after 6 years?\nremaining amount = 60(1 - ?)\nremaining amount = i(1 - r)^t\nenter the number that belongs in the green box.
Answer
Explanation:
Step1: Determine decay factor
The half - life is 3 years. In each half - life, half of the substance decays, so the decay rate $r=\frac{1}{2}$.
Step2: Determine number of half - lives
The time elapsed is $t = 6$ years and the half - life is 3 years. The number of half - lives $n=\frac{6}{3}=2$.
Answer:
$\frac{1}{2}$