Source carbon 14 used radiocarbon dating
Today, archeologists and paleontologists employ this technique to determine the age of organic materials (bones, teeth, wood, etc.) that are less than fifty thousand years in age.The theory is simple: Cosmic particles coming from outer space continuously collide with stable carbon-12 atoms in CO2 molecules, which are widespread in the atmosphere.Deep oceans, the biosphere, and carbonate rocks are giant reservoirs of carbon and with the addition of the atmosphere they constitute the carbon cycle of the Earth.
So, if you measure the amount of C14 in a dead organism, you can figure out how long ago it stopped exchanging carbon with its atmosphere.Each carbon-12 atom takes up two neutrons and is converted into a radioactive carbon-14 atom.Radioactive carbon-14 atoms rapidly mix and become uniform throughout the atmosphere. Since carbon is fundamental to life, occurring along with hydrogen in all organic compounds, the detection of such an isotope might form the basis for a method to establish the age of ancient materials.
Libby, a Professor of Chemistry at the University of Chicago, predicted that a radioactive isotope of carbon, known as carbon-14, would be found to occur in nature.
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