Radioactive decay
Not what you're looking for?
A threory of nuclear astrophysics is that all the heavy elements like uranium are formed in supernova explosions of massive stars, which immediately release the elements into space. If we assume that at the time of the explosion there were equal amounts of 235U and 238U, how long ago were the elements that formed our Earth released, given that the present 235U/238U ratio is 0.007? (The half-lives of 235U and 238U are 0.70 x 10^9 yr and 4.47 x 10^9 yr, respectively)
Purchase this Solution
Solution Preview
If N0 is the initial quantity, after a time t years, the amount of quantity of radioactive material left N = N0*exp(-lambda*t), where lambda = 0.693/half life.
<br><br>Given that N0 was same initially for ...
Purchase this Solution
Free BrainMass Quizzes
Classical Mechanics
This quiz is designed to test and improve your knowledge on Classical Mechanics.
Variables in Science Experiments
How well do you understand variables? Test your knowledge of independent (manipulated), dependent (responding), and controlled variables with this 10 question quiz.
The Moon
Test your knowledge of moon phases and movement.
Intro to the Physics Waves
Some short-answer questions involving the basic vocabulary of string, sound, and water waves.
Basic Physics
This quiz will test your knowledge about basic Physics.