Question

Pu is a nuclear waste byproduct with a half-life of 24,000 y. What fraction of the 239Pu present today will be present in 1000 y?

Answer 1

0.9715 Fraction of Pu-239 will be remain after 1000 years.

Step-by-step explanation:

`\lambda =\frac{0.693}{t_{(1)/(2)}}`

`A=A_o* e^(-\lambda t)`

Where:

`\lambda`= decay constant

`A_o` =concentration left after time t

`t_{(1)/(2)}` = Half life of the sample

Half life of Pu-239 =
`t_{(1)/(2)}=24,000 y`[

`\lambda =(0.693)/(24,000 y)=2.8875* 10^(-5) y^{-1]`

Let us say amount present of Pu-239 today =
`A_o=x`

A = ?

`A=x* e^{-2.8875* 10^(-5) y^(-1]* 1000 y)`

`A=0.9715* x`

`(A)/(A_0)=(A)/(x)=0.9715`

0.9715 Fraction of Pu-239 will be remain after 1000 years.