A moon rock collected by a U.S. Apollo mission is estimated to be 3.70 billion years old by uranium/lead dating.?

A moon rock collected by a U.S. Apollo mission is estimated to be 3.70 billion years old by uranium/lead dating. Assuming that the rock did not contain any lead when it was formed, what is the current mass of Pb206 in the rock, if it currently contains 1.230 g of U238? The half-life of U238 is 4.47×109 years.

Pb206 mass: 

4 Answers

Relevance
  • 5 months ago

    It happened Naturally

    So if there was any Lead involved, it would have been a remnant of a Supernova

    Kind of Figures in the Scheme of things and it was once part of Earth

    So things are the way they are

    Attachment image
    Source(s): Who needed a Nuke when there was Thiea ?
  • Zardoz
    Lv 7
    5 months ago

    It isn't assumed that the rock contained no lead. The sample is known to have contained no lead. They don't just grab any old rock.

    Source(s): [n] = 10ⁿ
  • Anonymous
    5 months ago

    The answer is 13.

  • 5 months ago

    half-life of U238 is 4.47×109 years WRONG

    perhaps 4.47×10^9 years  ??

    3.7 billion = 3.7e9

    3.7e9 / 4.47e9 = 0.828, number of half lives

    N(t) = N₀(1/2)^(t/th) 

    1.23 = N₀(1/2)^(0.828) 

    1.23 = N₀(0.563) 

    N₀ = 2.18 g

    N(t) = N₀(1/2)^(t/th) 

    N₀ is initial amount 

    N(t) is the amount remaining after time t 

    th is the half life time, ie, time for half the amount to decay 

Still have questions? Get answers by asking now.