Question
When Po decays, the product is Pb. The half-life of this decay process is 1.78 ms. If the initial sample contains $3.4\times 10^{17}$ parent nuclei, how many are remaining after 35 ms have elapsed? What kind of decay process is this (alpha, beta, or gamma)?
This is alpha decay. $4.1 \times 10^{11}$ nuclei remain.