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Uranium 238 has a half-life of about 4.5 billion years. All the 238U now on Earth was created in stars and has been here
Posted: Mon May 16, 2022 1:46 pm
by answerhappygod
- Uranium 238 Has A Half Life Of About 4 5 Billion Years All The 238u Now On Earth Was Created In Stars And Has Been Here 1 (43.54 KiB) Viewed 61 times
Uranium 238 has a half-life of about 4.5 billion years. All the 238U now on Earth was created in stars and has been here since the formation of Earth about 4.5 billion years ago. Consider a kilogram of pure 238 U present at the formation of the Earth. 1) Calculate the activity of the kilogram at that time. Sketch a graph of the activity of the uranium since then to the present day. Label the axes with appropriate numbers and units. Mark on your graph the half-life and the characteristic decay time. il) 238U decays through a chain of thirteen very short-lived radionuclides (longest half- live only 1600 years) before reaching a stable isotope of lead. If what remains of this uranium has for the last few million years been in a stable rock formation from which nothing escapes, approximately what activity will the rock have now?