C 14 dating
When these energetic neutrons collide with a nitrogen-14 (seven protons, seven neutrons) atom it turns into a carbon-14 atom (six protons, eight neutrons) and a hydrogen atom (one proton, zero neutrons).Since Nitrogen gas makes up about 78 percent of the Earth's air, by volume, a considerable amount of Carbon-14 is produced.The ratio of normal carbon (carbon-12) to carbon-14 in the air and in all living things at any given time is nearly constant.Maybe one in a trillion carbon atoms are carbon-14.Key Words: Radiocarbon dating, dinosaur, bone collagen, organic carbon, bone bio-apatite, fossil wood, amber, megafauna Introduction Bone collagen and soft tissue were recently reported as having been discovered in a Tyrannosaurus dinosaur femur bone as well as other fossil bones from the Cretaceous period of the geologic column by Mary H. The RC ages for extracted bone collagen for Smilodon femurs ranged from 12,650 ±160 to 28,000 ±1400 RC years BP (Before the Present). Libby, the inventor of the radiocarbon dating method, "There is no known natural mechanism by which collagen may be altered to yield a false age." It is common practice to determine the age of bones by radiocarbon (RC) dating of extracted bone collagen but not of dinosaurs because they are assumed to have become extinct 65 million years BP and, therefore, too old for RC dating.Nonetheless, dinosaur bone apatite had been successfully RC dated in the late 1980's/early 1990's and significant amounts of C-14 were detected and reported.
Total organic carbon and/or dinosaur bone bio-apatite was then extracted and pretreated to remove potential contaminants and concordant radiocarbon dates were obtained, all of which were similar to radiocarbon dates for megafauna. Walter Libby's team of collagen from "dense mid-shaft femur bones" of twelve extinct saber tooth tigers, [Smilodon] from the Le Brea Tar Pits of Los Angeles CA.To measure the amount of radiocarbon left in a artifact, scientists burn a small piece to convert it into carbon dioxide gas.Radiation counters are used to detect the electrons given off by decaying Carbon-14 as it turns into nitrogen.A very small percentage of carbon, however, consists of the isotope carbon 14, or radiocarbon, which is unstable.Carbon 14 has a half-life of 5,780 years, and is continuously created in Earth's atmosphere through the interaction of nitrogen and gamma rays from outer space.As you learned in the previous page, carbon dating uses the half-life of Carbon-14 to find the approximate age of certain objects that are 40,000 years old or younger.In the following section we are going to go more in-depth about carbon dating in order to help you get a better understanding of how it works.Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. 1979, 1986 © Harper Collins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 Cite This Source radiocarbon dating A technique for measuring the age of organic remains based on the rate of decay of carbon 14.Because the ratio of carbon 12 to carbon 14 present in all living organisms is the same, and because the decay rate of carbon 14 is constant, the length of time that has passed since an organism has died can be calculated by comparing the ratio of carbon 12 to carbon 14 in its remains to the known ratio in living organisms. Our Living Language : In the late 1940s, American chemist Willard Libby developed a method for determining when the death of an organism had occurred.Both Carbon-12 and Carbon-13 are stable, but Carbon-14 decays by very weak beta decay to nitrogen-14 with a half-life of approximately 5,730 years.After the organism dies it stops taking in new carbon.