If the fraction of the atoms of a radioactive material left after 120 years is 1/64, what is the half-life of the material?
A
24 years
B
20 years
C
10 years
D
2 years
Verified Correct Answer: B.
Physical Principles & Numerical Solution
Given amount remaining = \(\frac{1}{64}\)
= \(\frac{1}{64} = \frac{1}{(2)^{6}}\)
\(\therefore\) = \(\frac{120 \text {years}}{6}\) = 20 years
\(\Rightarrow\) T\(\frac{1}{2}\) = 20 years
Source: Myschool Past Questions Archive (Record #60747)