Posted by ARIANA on .
Pu239 has a halflife of 24110 y. If 1.00 kg of this isotope is present in the used fuel rods of a nuclear power plant approximately how long will it take for this amount of Pu239 to decay until there is less than 1 mg left ?
Please help. I do not know how to do this question.

CHEM 
DrBob222,
k = 0.693/t_{1/2}
Calculate k and substitute into the equation below.
ln(No/N) = kt
For No use 1000 g
For N use .001 g
k from above.
Solve for t in years.