Originally Posted by will641

ive been thinking of going back to school, but i think what you just wrote motivated me to put it off.

Originally Posted by Pelion

Maybe this example will make it clearer.

In a given second the parent has a 10% chance of decaying (long half life). The daughter has a 50% chance of decaying (short half life). We start with 1000 atoms of parent and no daughters.

Each second, 10% of the parent atoms are converted to daughter atoms, and 50% of the previous seconds daughter atoms decay away.


Time | Number of Parents | Number of daughters

0 | 1000 | 0
1 | 900 | 100
2 | 810 | 140
3 | 729 | 151
4 | 656 | 149
5 | 589 | 142


So even though this is a crappy example you can see that the number of daughter atoms is hovering around the same value. Even though the half life is much shorter for the daughter, there are still so many more parents that there are more parent decays than daughter decays per second (in the beginning). I hope this helps and I hope you get it before your exams

Goodluck!