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An explanation of radioactive carbon dating?   (I have to answer questions about how...

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mattlimey | Student, Grade 11 | Honors

Posted April 29, 2013 at 9:06 AM via web

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An explanation of radioactive carbon dating?

 

(I have to answer questions about how technology has impacted the knowledge about the evolution of life on Earth)

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pramodpandey | College Teacher | Valedictorian

Posted April 29, 2013 at 9:53 AM (Answer #1)

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The element carbon has two isotpes `^12C_6 and ^14C_6` .The difference is in the number of neutrons in the Carbon atom`^12C_6 has 6,^14C_6 has 8`  .The `^14C_6` is known as radio active carbon.

When an organism is alive they are mostly made of `^12C_6` , but absorb a bit of `^14C_6` from the atmosphere, this amount is known. So a living organism has a known ratio of `^12C_6` to `^14C_6`  .Once the organism dies, they can not  absorb  `^14C_6`from atmosphere.

Since `^14C_6` radioactive, so it s decays away at a fixed rate. So after a given period of time the organism will have the same amount of `^12C_6` as when it died, but some of the quantity of `^14C_6` will have decayed away. Since we know the rate of change, and the original percentage of `^14C_6`, we can calculate the time elapsed based on the current ratio of `^12C_6`  to `^14C_6` .This process of detrminig age is know as carbon dating.

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