Question 556: Atoms & Nuclei

Question

The activity of a radioactive sample is measured as N
0
counts per minute at t = 0 and N
0
/e counts per minute at t = 5 minutes. The time (in minutes) at which the activity reduces to half its value is

Accepted Answer

Now N = N
0
e
Ã¢ÂÂ$$\lambda $$t
$$ \Rightarrow $$ $${{{{N_0}} \over e}}$$ = N
0
e
Ã¢ÂÂ5t
$$ \Rightarrow $$ $$\lambda $$ = $${1 \over 5}$$ per minute
Further, $${{{N_0}} \over 2}$$ = N
0
e
Ã¢ÂÂÃÂ»(t)
t = $${1 \over \lambda }\ln 2$$ = 5log
e
2

Answer

$${\log _e}{2 \over 5}$$

Answer

$${5 \over {{{\log }_e}2}}$$

Answer

5log
10
2

Answer

5log
e
2

Atoms & Nuclei

The activity of a radioactive sample is measured as N 0 counts per minute at t = 0 and N 0 /e counts per minute at t = 5 minutes. The time (in minutes) at which the activity reduces to half its value is

Choose the correct answer: