11.) A 44 gram sample of Pb-211 (211 g/mol) is undergoing beta
decay in a 250 m3 room. After all of the lead has finished
decaying, what would a dosimeter that measures Roentgen read,
assuming a standard air density of 1.225 kg/m3 ? It may be helpful
to remember that 1 mole of electrons is 96485 Coulombs.