How much Plutonium 239 will remain after 20,000 years?

  • Thread starter yoleven
  • Start date
In summary, we are given a homework statement about the decay rate of Plutonium 239, which is 0.00284 percent per year. We are asked to find the remaining amount of P-239 after 20,000 years, starting with an initial sample size of 10 grams. Using the equation A = A0e^-rt and substituting the given values, we find that the remaining amount of P-239 is approximately 5.66 grams.
  • #1
yoleven
78
1

Homework Statement



Plutonium 239 (P-239) decays at a rate of 0.00284 percent per year. If the initial sample size
of P-239 is 10 g, how much will remain as P-239 after 20,000 years?

Homework Equations



A=A0e^-rt

The Attempt at a Solution


A=10e^-0.00284*20000
lnA=ln10+lne^-56.4
lnA=1-56.4
A=8.7*10^-25
This answer doesn't seem reasonable and I don't have confidence that I did everything correctly.
 
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  • #2
I tried the question again.
If A=A0*e^-rt
I want to find A
If I directly substitute and solve, I'll get..
A=10e^(-.00284*20000)
A=2.14*10^-24grams
 
  • #3
I think the problem is that you are putting 0.00284 in your equation. The 0.00284 is a percentage. So how else could you express that?
 
  • #4
Its a percentage so .00284 becomes .0000284?
A=10*e^(-.0000284*20000)
A=5.66grams
That sounds more realistic. Is this correct?
 
  • #5
Seems reasonable to me.
 
  • #6
Thank you.
 

1. What is the current amount of plutonium left on Earth?

As of 2021, it is estimated that there is approximately 2,400 tonnes of plutonium left on Earth.

2. How much plutonium was originally produced?

The total amount of plutonium produced in the world since the 1940s is estimated to be around 550 tonnes.

3. What is the rate of plutonium consumption?

The rate of plutonium consumption varies depending on the country and its use of nuclear energy. However, on average, about 20 tonnes of plutonium are consumed each year.

4. Will the amount of plutonium decrease in the future?

Yes, the amount of plutonium will continue to decrease as it is consumed and decays over time.

5. How long will the remaining plutonium last?

It is difficult to predict exactly how long the remaining plutonium will last, as it depends on various factors such as consumption rate and potential future discoveries. However, it is estimated that the current supply could last for several hundred years.

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