active products given by the atoaic boab, | We expected LIBuYs ( cont tinued) list of some length ranking the most important on dom, but the list was quite short and consisted of one iso and this is Strontios’°, Yow I've given a slightly incorrect impressions there're are interest in other iso bat the interest in gp as I understand it, far ex that interest in any other isotope, With sone justifi tion we can say that our problesa is reduced te the study of Sr’, Now this is in many respects a fortunate develapment, for cr? ts a beautifel thing as far as seasurexen is concerned. 1% would be very difficult te divice an isotope easier to detect in low quantities than sr79, This is the result of the fact that it has an yttrius daughter, the sr?? decay is a fora of yttrius 90, this a 20 year half-life, The yttrium decays with a 61 hour half-life and exits a 2 aillion volt beta ray. This be ray is about 1/2 willion volt. This is the chenistry of the tri-valence elements. This, of course, is an alkaline earth so the chanical separation of yttriua and strontius is quite a simple matter in principle. Now sees immediately that processes utilised could consist o two things. You can use the seperation of strontiua by Aiteelf as an element separated froaz tha sample and place it in the counter in equilibriua with its yttrium danghteP, its yttrium daughter being an equilibrius in a few days. Danse ttt 2 ‘oe ive . alee bh tae