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?
- 24 years
-
20 years
- 10 years
- 2 years
The correct answer is: B
Explanation
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
There is an explanation video available .