beljournalist.info - Encyclopedia > Radiocarbon dating
Radiocarbon dating is the use of a naturally occurring isotope of carbon to errors: there is never much 14C to begin with, and a half-life that long means that . Probably the best known form of radiometric dating is radiocarbon dating, very important to historians and archeologists as a method of determining the age of. a chemical analysis used to determine the age of organic materials based on their content of the radioisotope carbon; believed to be reliable up to 40,
Images for kids Radioactive decay All ordinary matter is made up of combinations of chemical elementseach with its own atomic numberindicating the number of protons in the atomic nucleus.
What is Carbon Dating?
Elements exist in different isotopeswith each isotope of an element differing in the number of neutrons in the nucleus. A particular isotope of a particular element is called a nuclide. Some nuclides are naturally unstable.
That is, at some point in time, an atom of such a nuclide will spontaneously change into a different nuclide by radioactive decay. The decay may happen by emission of particles usually electrons beta decaypositrons or alpha particles or by spontaneous nuclear fissionand electron capture.
beljournalist.info - Dictionary > Definition: radiocarbon dating
The age is calculated from the slope of the isochron line and the original composition from the intercept of the isochron with the y-axis. The mathematical expression that relates radioactive decay to geologic time is: This equation uses information on the parent and daughter isotopes at the time the material solidified.
- Radiocarbon Dating
- Radiometric dating facts for kids
This is well known for most isotopic systems. Plotting an isochron straight-line graph is used to solve the age equation graphically. It shows the age of the sample, and the original composition.
Radiometric dating Facts for Kids
Measurements were originally made by counting the radioactive decay of individual carbon atoms, but this was relatively insensitive and subject to statistical errors: Sensitivity and accuracy have since been greatly increased by the use of mass-spectrometric techniques, where the 14C atoms can be counted directly. Raw radiocarbon measurements are usually reported as years "before present" BP. This is the number of radiocarbon years beforebased on a nominal and fictitiously constant level of 14C in the atmosphere equal to the level.
Radiocarbon labs generally report an uncertainty, e.
Traditionally this includes only the statistical counting uncertainty and some labs supply an "error multiplier" that can be multiplied by the uncertainty to account for other sources of error in the measuring process. Additional error is likely to arise from the nature and collection of the sample itself, e.
It is sometimes stated that burnt material can be reliably dated to the time of burning. The maximum range of radiocarbon dating appears to be about 50, years, after which the amount of 14C is too low to be distiguished from background radiation.
The K-Ar and Uranium decay series are used in dating older objects see Radiometric dating.