the half - life of strontium - 90 is approximately 29 years. how much of a 150 g sample of strontium - 90…

the half - life of strontium - 90 is approximately 29 years. how much of a 150 g sample of strontium - 90 will remain after 116 years? remaining amount = ?(1 - )^ remaining amount = i(1 - r)^t
Answer
Answer:
$9.375$ g
Explanation:
Step1: Calculate number of half - lives
$n=\frac{116}{29}=4$
Step2: Identify initial amount and decay factor
$I = 150$ g, $r=\frac{1}{2}$
Step3: Use decay formula
Remaining Amount $=I(1 - r)^n=150\times(1-\frac{1}{2})^4$ $=150\times(\frac{1}{2})^4$ $=150\times\frac{1}{16}=9.375$ g