How radiocarbon dating works
The method can be used around 600-50k years to the past.
There are different methods of measuring isotope amounts.
Carbon-14 is produced in the upper troposphere and lower stratosphere by cosmic rays.(You can read up on radioactivity and isotopes here).Carbon-14, the radioactive version of carbon, is rare — it only makes up one trillionth of all the carbon in the world.(I'm already well-versed with the basics of nuclear chemistry).$^\ce$ is formed in the upper atmosphere from $^\ce$ so that the relative amount of $^\ce$ in the atmospheric $\ce$ is reasonably constant.The dating process is always designed to try to extract the carbon from a sample which is most representative of the original organism.In general it is always better to date a properly identified single entity (such as a cereal grain or an identified bone) rather than a mixture of unidentified organic remains.The cosmic rays generate neutrons which knock a proton out of nitrogen-14 to produce carbon-14.This carbon quickly combines with oxygen to form carbon dioxide.For radiocarbon dating to be possible, the material must once have been part of a living organism.This means that things like stone, metal and pottery cannot usually be directly dated by this means unless there is some organic material embedded or left as a residue.