Discussion on Nuclear Chemistry

 1) If the half-life of 14056Ba is 12.75 days, how many atoms of 14056Ba will be left after 9 weeks if there were initially 2.4 mol of atoms?

2) How long will it take 3.8 x 1024 atoms of 10047Ag to disintegrate to 2.93 x 1023 atoms if the half life of 10047Ag is 24.6 seconds?

3) Radioactive copper, 6429Cu, is found in quantities exceeding pollution standards in the sediments of a reservoir in a routine check on Monday. The standard allows up to 14 ppm/cubic meter of sediment. On Monday, 59ppm/cubic meter were measured.
The half life of 6429Cu is 12.7 hours. When will the pollution level return to 14ppm?

4) An unidentified corpse was discovered on 21 April at 7:00 AM. The pathologist discovered that there were 1.24 x 1037 atoms of 3215P remaining in the victim's bones and placed time of death sometime on 15 March. The half life of 3215P is 14.28 days.
How much 3215P was present in the bones at the time of death?