# Problem: The half-life of I-131 is 8 days. After 24 days of the original amount of I-131 remains. A. One halfB. One thirdC. One fourthD. One eighthE. One sixteenth

###### FREE Expert Solution

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:

where:

[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:

85% (311 ratings)
###### Problem Details

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

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the First Order Half Life concept. You can view video lessons to learn First Order Half Life. Or if you need more First Order Half Life practice, you can also practice First Order Half Life practice problems.