Carbon 14 dating essay

3364 Words Oct 7th, 2013 14 Pages
Carbon-14 Dating: an Invaluable Yardstick in the Chronology of Humans

Archeologists use many methods to analyze data from the past. One scientific tool they use is to analyze the radioactive decay of chemical elements found in plant and animal remains, pottery, and even in rocks. Radiocarbon dating, also known as carbon-14 dating, has been one of the most important radioisotope dating methods used. This scientific tool, which was first developed by Willard F. Libby in the late 1940s, has significantly improved the accuracy of assigning dates to past events and artifacts as far back as 70,000 years. It is helping archaeologists, geologists, and anthropologists reconstruct the world’s history by filling in some of the many blank dates
…show more content…
Although radiocarbon dating methods have improved tremendously, Libby’s overall methodology is still utilized and accepted as a dating technique. It is based upon the fact that carbon-14 is a radioactive, unstable isotope of carbon-12 since its molecular composition has two more neutrons than protons. Carbon-14 is made when cosmic rays enter the earth’s atmosphere and collide with nitrogen atoms. The unattached carbon neutrons then combine with nitrogen-14 atoms to become carbon-14 (Nitrogen-14 + neutron → Carbon-14 + proton). As the resulting carbon-14 atoms drift down towards the earth’s surface they combine with oxygen to make carbon dioxide. This carbon dioxide includes the stable, common isotope carbon-12 and also tiny amounts of radioactive carbon-14. Both kinds of carbon, C-14 and C-12, are absorbed and used by plants and trees during the photosynthesis process and become part of their cellulose structure. Animals then eat these plants containing carbon-14 and carbon-12 and thus forms of carbon enter their tissues. When plants and animals die, they no longer absorb carbon from the atmosphere and the trace amount of carbon-14 in them starts to slowly decay back to nitrogen (Carbon-14 → Nitrogen-14 + Beta (β)). Beta particles are single electrons that are free from atoms and carry a negative charge (DeYoung 2005:25). At the point of death,

More about Carbon 14 dating essay

Open Document