The decay constant , for a given radioactive sample, is 0.3465 `"day"^(-1)` .What percentage of this sample will get decayed in a period of 4 days ?

Options

A. `100%`
B. `50%`
C. `75%`
D. `10%`

Answer

C

Explanation

Here, `lambda=0.3465 "day"^(-1) ` ,t=4 days
`T_(1//2)=0.693/lambda=0.693/0.3465`=2 days
`therefore n=1/T_(1//2)=4/2`=2
Hence, sample left decayed after a period of 4 days.
`N/N_0=(1/2)^2 =(1/4)`=25%
`therefore ` Sample decayed = 75%