question_answer 48)

  Consider a radioactive nucleus A which decays to a stable nucleus C through the following sequence: A ® B® C Here, B is an intermediate nucleus which is also radioactive. Considering that there are N0 atoms of A initially, plot the graph showing the variation of number of atoms of A and B versus time.

Answer:

    The given sequence of radioactive decay is A ® B® C C is stable At t=0, N0 and NB =0.                        As time passes on, (increases. NA falls off exponentially to zero  The number of atoms of B goes on increasing with time, becomes maximum and finally decays to zero  following exponential decay law  The variation of the number of atoms of A and B versus time is shown in Fig. 8 (EP).4.