A radioactive isotope decays according to the equation where Nt is the amount of
ID: 817102 • Letter: A
Question
A radioactive isotope decays according to the equation
where Nt is the amount of sample at time t, N0 is the original amount of sample, and ? is the decay constant. An unknown amount of an unidentified isotope is left to decay, and periodic measurements of the remaining isotope are recorded in the table below.
Time(days) amount of isotopes (Moles)
12.0 6.6
36.0 0.80
50.0 0.23
85.0 0.011
112.0 0.0010
1. What is ?, the decay constant?
2.What is N0, the original amount of radioactive material?
Explanation / Answer
12.0 6.6
36.0 0.80
50.0 0.23