Physics

Problem

For a certain radioisotope the straight-line graph of

\ln N

against time passes through the points

(t=0\,\text{s},\,\ln N=22)

and

(t=40\,\text{s},\,\ln N=20)

. (a) Determine the numerical value of the decay constant

\lambda

. (b) Calculate the half-life of the isotope. (c) If the initial number of nuclei at

t=0

was

3.5\times10^{9}

, find the number of undecayed nuclei remaining after

2.0\text{ min}

. a. (a) Calculation of

\lambda

from graph points b. (b) Determination of half-life c. (c) Number of nuclei after

2.0\text{ min}