carbon-14 dating
...wn: C14 has a half-life of 5730 years. Basically this means that half of the original amount of C14 in organic matter will have disintegrated 5730 years after the organisms death; half of the remaining C14 will have disintegrated after another 5730 years and so forth. After about 50,000 years, the amount of C14 remaining will be so small that the fossil can't be dated reliably. C-14 becomes attached to complex organic molecules through photosynthesis in plants and becomes part of their molecular makeup. Animals eating those plants in turn absorb Carbon-14 as well as the stable isotopes. To measure the amount of radiocarbon left in a fossil, 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. In order to date the fossil, the amount of Carbon-14 is compared to the amount of Carbon-12 (the stable form of carbon) to determine how much radiocarbon has decayed. Basically, to find the date of something, scientists look at the ratio of carbon-14 to carbon-12 because when organisms die, they don’t gain carbon-14 from the atm...