Only a tiny percentage of carbon atoms are carbon-14. Figure below shows carbon dioxide, which forms in the atmosphere from carbon-14 and oxygen.For example, the half-life of carbon-14 is 5730 years. Over the next 5730 years, half of the remaining amount will decay. How many grams will there be in another 5730 years?So the organism contains less and less carbon-14 as time goes on.

For example if you have a fossil trilobite and it was found in the wheeler formation.

Article: amino acid acid dating is a dating technique [5][6][7][8][9] used to estimate the age of a specimen in paleobiology, archaeology, forensic science, taphonomy, sedimentary geology and other fields.

Information: dating methodologies in ve dating methods in archaeology are similar to some of those applied in geology.

Here is the same diagram i showed above, but this time i've squished and stretched parts of it to fit a linear time scale on the right.

The technique often cannot pinpoint the date of an archeological site better than historic records, but is highly effective for precise dates when calibrated with other dating techniques such as tree-ring additional problem with carbon-14 dates from archeological sites is known as the "old wood" problem.

But if i say that an event dates back to the time that the moon was getting hammered by huge impacts, or if it dated back to the time after the impacts when the mare lavas were flowing out on to the moon's surface, in either case the event would have taken place billions of years ago; and that's precise enough for almost any public communication the ages are so uncertain for the moon, what about the ages of mars and mercury? Absolute ages are much different from relative ages. Absolute ages are determined by radiometric methods, such as carbon-14 dating. Radioactive decay is the breakdown of unstable elements into stable elements. But carbon-12 has 6 neutrons and carbon-14 has 8 neutrons. Neutrons in cosmic rays strike nitrogen atoms in the atmosphere. Carbon in the atmosphere combines with oxygen to form carbon dioxide.To understand this process, recall that the atoms of all elements contain the particles protons, neutrons, and electrons. Plants take in carbon dioxide during photosynthesis. Like other unstable isotopes, carbon-14 breaks down, or decays.Most earth geologists don't talk about that tologists have used major appearances and disappearances of different kinds of fossils on earth to divide earth's history -- at least the part of it for which there are lots of fossils -- into lots of eras and periods and epochs.Stimulated luminescence (osl) dating constrains the time at which sediment was last exposed to light.So carbon-14 dating is useful for specimens younger than 50,000 years old. But radiocarbon dating is very useful for more recent events.