Question

Sr-90 beta-minus decays to Y-90. At time 0, a given sample contains 1.0 GBq of Sr-90 (half-life 29.12 yr) and 0 GBq of its daughter, Y-90, (half-life 64.0 hr).

(a) What will be the activity of each nuclide after 7 days (You need to obtain the expressions for the concentrations of Sr and Y as a function of time and then plug in t=7 days).
(b) What will be the activity of each nuclide after 29.12 years? (You can either use the expressions obtained in (b) or use your knowledge of decay kinetics).

Answer 1