Exposing modern forgers

The art market is booming and commercialisation has increased apace. As a result, bad actors are tempted to copy a historical painting in the hope of making a quick buck. These fakes are most easily detected if it can be ...

Research reveals evidence of climate change in the Yukon permafrost

A new University of Toronto study confirms that recent climate warming in the central Yukon region has surpassed the warmest temperatures experienced in the previous 13,600 years, a finding that could have important implications ...

Study suggests giant sloth did not make it to Holocene

A team of researchers from the National University of Central Buenos Aires, Olavarría, Stafford Research and La Brea Tar Pits and Museum, has found evidence that suggests the giant sloth went extinct before the onset of ...

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Carbon-14, 14C, or radiocarbon, is a radioactive isotope of carbon discovered on February 27, 1940, by Martin Kamen and Sam Ruben at the University of California Radiation Laboratory in Berkeley, though its existence had been suggested already in 1934 by Franz Kurie. Its nucleus contains 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method to date archaeological, geological, and hydrogeological samples.

There are three naturally occurring isotopes of carbon on Earth: 99% of the carbon is carbon-12, 1% is carbon-13, and carbon-14 occurs in trace amounts, e.g. making up as much as 1 part per trillion (0.0000000001%) of the carbon in the atmosphere. The half-life of carbon-14 is 5,730±40 years. It decays into nitrogen-14 through beta decay. The activity of the modern radiocarbon standard is about 14 disintegrations per minute (dpm) per gram carbon.

The atomic mass of carbon-14 is about 14.003241 amu. The different isotopes of carbon do not differ appreciably in their chemical properties. This is used in chemical research in a technique called carbon labeling: some carbon-12 atoms of a given compound are replaced with carbon-14 atoms (or some carbon-13 atoms) in order to trace them along chemical reactions involving the given compound.

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