Polonium-210, an alpha emitter, has a halflife of 138.4 days. Suppose you were to collect the helium gas originating from the alpha particles. How many milliliters of helium gas at standard temperature and pressure would you collect from 1.000 g of polonium dioxide, PoO₂, in a period of 138.4 days? [Assume all the polonium in the sample is ²¹⁰Po, molar mass 209.98287 g/mol. Alpha emission from polonium-210 yields the nonradioactive isotope lead-206; see Problem 16.103.]

Data from Problem 16.103

Polonium-210 is an alpha emitter and has a half-life of 138 days.

Write the equation for the radioactive decay of polonium-210.

How long will it take before only 5.00% of the original amount of ²¹⁰Po in a sample remains?