Calculate Radioactive Decay for a Radioactive Metal by the number of Atoms Decayed

Question

(A) A radioactive metal atom decays by emitting an alpha particle. The alpha particles are collected as an ideal gas. The volume of the gas collected was 12.05 mL at 765 mmHg and 23°C. How many atoms decayed during the period of the experiment?

(B) You vaporize a liquid substance at 100°C and 755 mmHg. The volume of 0.548 g of vapor is 237 mL. What is the molecular weight of the substance?

Summary

The question belongs to Chemical Engineering and it is about a radioactive metal atom decaying by emitting an alpha particle. The alpha particles are collected as an ideal gas. The question is how many atoms have decayed in this process. And the second question is about a liquid being vaporized. The molecular weight of the vapor is to be calculated.

Note: The solution is in handwritten format.