For the following calculations SHOW ALL WORK!! (6 points each)

7. The half- life of molybdenum-99 is 67.0 hours. How much of a 1.000 gram sample
remains after 335 hours.


8. Determine the average atomic mass of gallium if 60.00% of its atoms have a mass of
68.926 amu and 40.00% have a mass of 70.925 amu.