Question

Question #bf230

Answer 1

Pu-239 has a half life of 24100 years.

Explanation:

Decay reaction:

`C=C_0*e^-(r*t)`

First let me compute r (decay coefficient) for Pu-239.

`5=10*e^-(r*24100)`

`ln 0.5 = -24100*r`

`r = 0.00002876` 1/year

Now you can compute what amount of Pu-239 will be after 6500 years.

`C = 10*e^-(0.00002876*6500)`

`C=10*0.8295`

`C=8.295` grams of Pu-239.

Your answer is 8.295 grams.

Reference:

Half-life of Plutonium 239. Retrieved on the internet May 29, 2017. hypertextbook(dot)com(slash)facts(slash)1999(slash)JaniceChing(dot)shtml