I am trying to solve the following problem for my graduate course in isotope geochemistry. If 1 g of 226Ra is separated from its decay products and then placed in a vessel, how much helium (cm3) will accumulate in the vessel in 60 days? Here is what I know. The decay series from 226Ra to Lead 206 (the final stable daughter) includes five alpha decays, and these will be the source of He2+ ions. I am assuming secular equilibrium because the half-life of 226Ra is >> 60 days. Ultimately, I know I will have to determine how many alpha particles are created in order to answer the question. However, I am not sure how to get started on the problem and was hoping someone could offer some help.