Radioactive dating

Radioactive dating - 11 atoms of carbon When an organism dies the carbon-14 slowly decays so the proportion of C-14 is reduced over time Carbon-14

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Radioactive dating Radioactivity is often used in determining how old something is; this is known as radioactive dating. When carbon-14 is used, as is often the case, the process is called radiocarbon dating, but radioactive dating can involve other radioactive nuclei. The trick is to use an appropriate half-life; for best results, the half-life should be on the order of, or somewhat smaller than, the age of the object. Carbon-14 is used because all living things take up carbon from the atmosphere, so the proportion of carbon-14 in the carbon in a living organism is the same as the proportion in the carbon-14 in the carbon in the atmosphere. For many thousands of years this proportion has been about 1 atom of C-14 for every 8.3 x 10
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Unformatted text preview: 11 atoms of carbon. When an organism dies the carbon-14 slowly decays, so the proportion of C-14 is reduced over time. Carbon-14 has a half life of 5730 years, making it very useful for measuring ages of objects that are a few thousand to several tens of thousands of years old. To measure the age of something, then, you measure the activity of carbon-14, and compare it to the activity you'd expect it to have if it was brand new. Plugging these numbers into the decay equation along with the half-life, you can calculate the time period over which the nuclei decayed, which is the age of the object. An example...
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This note was uploaded on 11/22/2011 for the course PHY PHY2053 taught by Professor Davidjudd during the Fall '10 term at Broward College.

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