1. Growth of Daughter Activities

2. Parent to next generation(s)
Consider the decay of a parent nuclide to succeeding nuclide generations, e.g.,
(12 3 4…)
Assume that N1(0) = N0;
N2(0) = N3(0) = N4(0) =0…
Then the differential equations describing the rate of change of a given generation are -

3. Parent to next generation(s)
Consider special cases:
2 = 0  Nuclide 2 is stable!

4. Parent to next generation(s)
Consider special cases:
1  0 ; 1 << 2 ; 1 << 3 ; 1 << 4 …

5. Parent to next generation(s)
Consider special cases:
1 << 2
As t becomes large …
Secular equilibrium

6. Parent to next generation(s)
Consider special cases:
1 < 2
Transient equilibrium

7. Parent to next generation(s)
Consider special cases:
1 > 2
Decays fast!