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B Carbon dating

  1. Mar 6, 2016 #1
    Carbon 14 with half life of 5730 years has been used for many years to determine the age of objects. Recently plutonium 210 with half life of 21 years has been used as an alternative. Why plutonium 210 is more suitable compare to carbon 14?
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  3. Mar 6, 2016 #2


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    There is no plutonium-210. Do you mean polonium-210? It has a half-life of just 140 days.
    Shorter half-lifes are better for more recent samples (as the change in the amount of longer-living stuff is not large). longer half-lifes are better for older samples (where all the short-living stuff is long gone).
    Then you also need a suitable comparison value, the material has to contain your radioisotope in sufficient quantity, it should not exchange your isotope with the environment, and various other things to consider.
  4. Mar 6, 2016 #3


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    Plutonium has no isotope with the number 210.
    Where did you see this? Can you put a link?

    The first isotope with the number 210 that comes into my mind is Polonium, but it has a half life of 138 days and there are only trace amounts of them found in the nature- insufficent for dating analyses. Lead-210 has a half life of roughly 22 years, but then again, with so little amounts, it is hard to analyse.

    You might want to look at this thread.
  5. Mar 6, 2016 #4


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    Ignoring the possible wrong isotope - there are very many isotopes that are used for dating items, not just carbon-14. Here are some of them: 10Be, 14C, 26Al, 32Si, 36Cl, 41Ca, 53Mn, 59Ni, 99Tc, 129I, 236U, 237Np, 239Pu, 240Pu, 242Pu and 244Pu

    For example, cosmogenic isotopes like 10Be, 26Al, and 36Cl are used for surface dating of geological samples. You wouldn't use C14 for this. Depending on the lifetime and the chemistry, different isotopes are used to answer different questions.
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