A radioactive element is disintegrating having half-life 6.93 s. The fractional change in number of nuclei of the radioactive element during 10 s is

Options

A. (a) 0.37
B. (b) 0.63
C. (c) 0.25
D. (d) 0.50

Answer

B

Explanation

`lambda=(1n2)/(t_(1//2))=0.693/6.93=1/10sec^-1`
`N=N_0e^(-lambdat)`
`:.N/N_0=e^(-lambdat)=e^(-(1/10)(10))`
`=e^-1~~0.63`