The Theory of Nuclear Astrophysics Is That All the Heavy

question 39

Short Answer

The theory of nuclear astrophysics is that all the heavy elements like uranium are formed in the interior of massive stars. These stars eventually explode, releasing these elements into space. If we assume that at the time of the explosion there were equal amount of U-235 and U-238, how long ago did the star(s) explode that released the elements that formed our Earth? The present U-235/U-238 ratio is 0.0070. [The half-lives of U-235 and U-238 are 0.7 × 10⁹ yr and 4.47 × 10⁹ yr.]

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Definitions:

Future Value

The worth of a current asset on a future date, calculated by estimating its growth rate over a specific period.

Compound Interest

Interest on both the initial principal and the accumulated interest from previous periods on a deposit or loan.

Future Value

The worth of an asset or cash at a specified date in the future that is equivalent in value to a specified sum today.

Compounded Quarterly

Referring to interest that is calculated and added to the principal amount at the end of each quarter, leading to exponential growth.