Larry, I'm not sure if today's scientists use the same terms for the natural decay isotopes as "old gits" like me, but here goes!
Uranium 235 & 238 naturally decay by different routes, but eventually arrive at;
uranium > ionium > radium.
Radium decays in a sequence of isotopes.
RaA is radon: 226-4[ ie helium, the alpha particle ] > mass 222 approx + energy.
Then decay proceeds >
RaB, isotope of lead>
RaC, isotope of bismuth>
RaD, isotope of lead>
RaE, isotope of bismuth>
RaF, Mme Curie's polonium>
RaG, lead, inactive, mass 206>
Each decay releases either/ and / or alpha particles, beta rays, gamma rays + heat. The decay product falls into a group 2 places lower in the periodic table for release of an alpha particle. For a beta ray release change, the decay product rises one place higher in the periodic table than the parent substance.
In an ore, these isotopes will exist in proportion to their respective half-lives, so we get them all.
Thorium and Actinium ores will exhibit similar series of isotopes, in proportion, except that the final, inactive, lead isotopes will be ThD mass 208 and AcD mass 207 respectively. I very much doubt that Thorium ores can be found completely free of Uranium, and in any case Uranium and Thorium both produce radioactive lead and bismuth isotopes. These cannot be separated chemically of course- only a centrifuge can do that.
OOOOOPS! We know what you can make with centrifuges!
No, Doofy, not milkshakes.
Alan
