Q:

When studying radioactive​ material, a nuclear engineer found that over 365​ days, 1,000,000 radioactive atoms decayed to 973 comma 635 radioactive​ atoms, so 26 comma 365 atoms decayed during 365 days. a. Find the mean number of radioactive atoms that decayed in a day. b. Find the probability that on a given​ day, 51 radioactive atoms decayed.

Accepted Solution

A:
Answer:A. number of decayed atoms = 73.197Step-by-step explanation:In order to find the answer we need to use the radioactive decay equation:[tex]N(t)=N0*e^{kt}[/tex] where:N0=initial radioactive atomst=timek=radioactive decay constantIn our case, when t=0 we have 1,000,000 atoms, so:[tex]1,000,000=N0*e^{k*0}[/tex][tex]1,000,000=N0[/tex]Now we need to find 'k'. Using the provied information that after 365 days we have 973,635 radioactive atoms, we have:[tex]973,635=1,000,000*e^{k*365}[/tex][tex]ln(973,635/1,000,000)/365=k[/tex][tex] -0.0000732=k[/tex]A. atoms decayed in a day:[tex]N(t)=1,000,000*e^{-0.0000732t}[/tex][tex]N(1)=1,000,000*e^{-0.0000732*1}[/tex][tex]N(1)= 999,926.803[/tex]Number of atoms decayed in a day = 1,000,000 - 999,926.803 = 73.197B. Because 'k' represents the probability of decay, then the probability that on a given day 51 radioactive atoms decayed is k=0.0000732.