8 April 2014
Radio Isotopic Dating
An isotope is an atom of the same element with different number of neutrons. Sometimes the isotope is unstable which causes the isotope to change into a different atom over a certain period of time. By comparing the ratio of the original atom to the product that were in the beginning sample with the ratio of the products at the present time, scientists are able to determine the age of a substance. Radio isotopic dating, or radioactive dating is the calculation of a substance's age by measurement of the radioactive material it contains or of the amount of natural atomic fission that has occurred in the substance. By using these dating methods, scientists have been able to determine the age of many things for example, dead organisms, rocks, and even the Earth.
One type of radio isotopic dating is recognized as carbon dating. The radioactive decay of carbon-14 is used in carbon dating. Carbon-14 atoms are equally distributed over Earth's biosphere. These atoms are combined with carbon-12 and carbon-13. Organisms contain the same ratio of carbon-14 to carbon-12 and carbon-13 because organisms are always taking in carbon. When the plants intake carbon dioxide, they are using these various carbon isotopes. When a plant is eaten by an animal, the carbon-14 atoms are then transferred to the animal. Once the organism dies, the carbon-14 continues to decay. Encountering beta decay, the carbon-14 forms nitrogen-14. In order to estimate the age of an object, the ratio that is present during the sampling is compared to the almost steady ratio present in the atmosphere. This kind of dating works best with objects that aren't too old.
With objects that are too old to be dated with carbon dating, researchers use the decay of uranium-238 to lead-206. This kind of dating use primarily used in dating objects some of which are rocks.
This is a figure of the decay series...
Cited: "How Old Is the Earth: Radioisotopic Dating". For Dummies. Web. April 03, 2014.
Buthelezi, Thandi, Laurel Dingrando, Nicholas Hainen, Cheryl Wistrom, and Dinah Zike. Chemistry Matter and Change. Columbus: Glencoe/McGraw- Hill School Pub Co, 2013. Print
"Uranium-Thorium-Lead Dating Method". Uranium-Thorium-Lead Dating Method. Web. April 03, 2014.
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