First Order Half Life Video Lessons

Concept:

Problem: A sample of F-18 has an initial decay rate of 1.6×105 /s .How long will it take for the decay rate to fall to 2.6×103 /s ? (F-18 has a half-life of 1.83 hours.)

FREE Expert Solution

We’re being asked to determine the time will it take for the decay rate of F-18 to fall to 2.6x103/s.

Recall that radioactive/nuclear decay of isotopes follows first-order kinetics, and the integrated rate law for first-order reactions is:

$\overline{){\mathbf{ln}}{\mathbf{\left[}\mathbf{N}\mathbf{\right]}}_{{\mathbf{t}}}{\mathbf{=}}{\mathbf{-}}{\mathbf{kt}}{\mathbf{+}}{\mathbf{ln}}{\mathbf{\left[}\mathbf{N}\mathbf{\right]}}_{{\mathbf{0}}}}$

where:

[N]t = concentration at time t

k = decay constant

t = time

[N]0 = initial concentration.

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Problem Details

A sample of F-18 has an initial decay rate of 1.6×105 /s .

How long will it take for the decay rate to fall to 2.6×103 /s ? (F-18 has a half-life of 1.83 hours.)

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.