1. The problem statement, all variables and given/known data In a chain radioactive disintegration,the half-life of the parent and daughter nuclide are 10 years and 25 years respectively.if the disintegration process is at its equilibrium stage with the parent no. of nuclei equal to 5* 10^8, the daughter no. of nuclei will be 2. Relevant equations t1/2 = 0.639/λ n/n0=(1/2)^(t/(t1/2)) n/n0=##e^-λt## 3. The attempt at a solution t11/2 = 10 years t21/2 = 25 years N=No (because its at equilibrium) →e^-tλ=1 tλ=0??