Biology Forum Community General Discussion Question about Carbon 14

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    • #10980

      I have a question about the half lives of carbon 14. Does anyone here understand how they can test half lives, or how they calculate it today?

      The half life of C-14 is 5730 years which means 50% of it has turned into nitrogen after 5730 years, then 25% of it after 11640 years, and then 12.5% 17190 years later, and so on.

      I guess what seems strange to me is there would be some atoms that would decay during the first 5730 years, whereas .781% of the atoms would take 40110 years to decay. Some would take longer. That doesn’t make sense to me.

      If you put similar materials out in the same environment, such as wood or a dead animal they decay at pretty much the same rate. Why is there such a difference in atoms?


    • #89412

      Radioactive isotopes (such as C14) usually have too many neutrons relative to the number of protons in their nuclei, and so have a hard time holding their nuclear particles together. The rate at which they decay is variable but usually gets faster as the atom gets larger. Atoms with a more "balanced" ratio of protons to neutrons (such as C12) tend to decay very slowly or not at all.

      That’s not exactly a text-book definition but that’s the gist of it. Here’s a link with more info:

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