Radiocarbon Dating
...air to make carbon dioxide. Plants absorb the radioactive carbon through photosynthesis and use it to make glucose molecules. Since plants are producers and are at the bottom of the food chain, the carbon-14 is transferred to all living organisms (Taylor 2). 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. The radioactive carbon is continually decaying and is being replaced by the normal carbon-12. When an organism dies, it stops taking in carbon and the carbon-14 continues to decay with a half-life of 5700 years. By comparing the ratios of the carbon isotopes present in the remains of an organism to the ratios in a living organism, it is possible to determine its age. The most modern and useful technique used to determine age is using an accelerator mass spectrometry (AMS) which directly counts the amount the residual carbon-14 ...