How long will it take for the radioisotope Rn-222 to decay to 54.4 g if the half-life of Rn-222 is 3.8235 days, starting with the following. (Isotopic mass of Rn-222 is 222.017570 g/mol)
a) 80.1 g Rn-222
b) 10.6 mol Rn-222