A 10 g sample of a pure radioactive isotope X has a half-life of 12 h
CHEMISTRY · Subjective · US High School · Chemistry · Atomic Structure & Nuclear · Atomic Structure & Nuclear
Problem
A 10 g sample of a pure radioactive isotope X has a half-life of 12 h. Exactly one-quarter of the undecayed atoms present is withdrawn from the container every 6 h, while the rest of the sample is left to continue decaying.
(i) Determine how many half-lives elapse during the total observation time of 36 h.
(ii) Calculate the mass of isotope X that remains in the container at the end of 36 h after the three successive withdrawals.
(iii) If the sample had been left completely undisturbed for the same 36 h, what mass of isotope X would have been left? Compare this value with the result of part (ii) and comment briefly on the difference.