A radionuclide consists of two isotopes

PHYSICS · Multi-part · A Level · Physics · Nuclear physics · Nuclear physics

Problem

A radionuclide consists of two isotopes. One isotope decays by α\alpha emission and the other by β\beta emission, with half-lives t1=405 st_1=405\ \mathrm{s} and t2=1620 st_2=1620\ \mathrm{s}, respectively. At t=0t=0, the probabilities of obtaining α\alpha and β\beta particles from the radionuclide are equal. Calculate their respective probabilities at t=1620 st=1620\ \mathrm{s}. If the total number of nuclei at t=0t=0 is N0N_0, calculate the time tt when the total number of undecayed nuclei equals N0/2N_0/2. Given log⁡102=0.3010\log_{10}2=0.3010, log⁡105.94=0.7742\log_{10}5.94=0.7742, and x4+4x−2.5=0x^4+4x-2.5=0 has root x=0.594x=0.594. (a) Calculate the respective probabilities of obtaining α\alpha and β\beta particles at t=1620 st=1620\ \mathrm{s}. (b) Calculate the time at which the total number of undecayed nuclei is N0/2N_0/2.

Related theory

Browse the problem library