Question 209: Atoms & Nuclei

Question

What is the half-life period of a radioactive material if its activity drops to $$1 / 16^{	ext {th }}$$ of its initial value in 30 years?

Accepted Answer

$$\because$$ $$A = {{{A_0}} \over {{2^{{t \over {{T_{1/2}}}}}}}}$$
$$ \Rightarrow {2^{{t \over {{T_{1/2}}}}}} = {{{A_0}} \over A} = 16$$
$$ \Rightarrow {t \over {{T_{1/2}}}} = 4$$
$$ \Rightarrow {{30} \over {{T_{1/2}}}} = 4$$
$$ \Rightarrow {T_{1/2}} = {{30} \over 4}$$
$$ = 7.5$$ years

Answer

9.5 years

Answer

8.5 years

Answer

7.5 years

Answer

10.5 years

Atoms & Nuclei

What is the half-life period of a radioactive material if its activity drops to $1 / 16^{\text {th }}$ of its initial value in 30 years?

Choose the correct answer: