Question

Review Constants Per A sample of F - 18 has an initial decay rate of 1.3x105 /s Part A How long will it take for the decay rate to fall to 1.7x10°/s? (F - 18 has a half-life of 1.83 hours.) VAXD Submit Request Answer

Answer 1

Half life is 1.83 hours...

Thus, rate constant -

in2 0.693 1.83 = 0.379 hour-1

Now , according to decay rate equation

$(\frac{1}{\lambda })ln\frac{A_{0}}{A}=t$

..t=41) n1.3 x 10 0.379" 1.7 x 103

iit= 11.443 hours

[ANSWER]