Question

A radioactive isotope has a life of T years. How long will it take the activity to reduce to (a) `1%` of its original activity?
A. `3.2T yr`
B. `4.6T yr`
C. `6.6T yr`
D. `9.2T yr`

Answer 1

Correct Answer - C
form `A=A_(0)=N/(N_(0)) =(1/2)^(n) =1/100`
`:. n(log1-log2)=log1-log100`
`n(0-0.3010)=0-2`
`n=2/0.3010=6.6`
`t=nT=6.6Tyrs`