We’re being asked to determine how much of the original amount of I-131 is left after 24 days if the half-life of I-131 is 8 days.
Recall that radioactive/nuclear decay of isotopes follows first-order kinetics, and the integrated rate law for first-order reactions is:
[N]t = concentration at time t
k = decay constant
t = time
[N]0 = initial concentration.
Also, recall that half-life is the time needed for the amount of a reactant to decrease by 50% or one-half.
The half-life of a first-order reaction is given by:
The half-life of I-131 is 8 days. After 24 days of the original amount of I-131 remains.
A. One half
B. One third
C. One fourth
D. One eighth
E. One sixteenth
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