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Carbon-14, C-14, 14 C or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic matter is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues (1949) to date archaeological, geological and hydrogeological samples.
Two are stable and not radioactive: carbon-12 (12 C), and carbon-13 (13 C); and carbon-14 (14 C), also known as "radiocarbon", which is radioactive. The half-life of 14 C (the time it takes for half of a given amount of 14 C to decay) is about 5,730 years, so its concentration in the atmosphere might be expected to decrease over thousands of ...
2 again, dried, and converted to carbon by passing it over heated magnesium. Hydrochloric acid was added to the resulting mixture of magnesium, magnesium oxide and carbon, and after repeated boiling, filtering, and washing with distilled water, the carbon was ground with a mortar and pestle and a half gram sample taken, weighed, and combusted ...
Records show that from the 1940s through the 1960s, it was not uncommon for local hospitals, labs and other industrial operations to dispose barrels of tritium, carbon-14 and other similar waste ...
It has been suggested that an "island effect" might exist, by analogy with the mechanism thought to explain the hemisphere effect: since islands are surrounded by water, the carbon exchange between the water and atmosphere might reduce the 14 C / 12 C ratio on an island. Within a hemisphere, however, atmospheric mixing is apparently rapid ...
The calculation of radiocarbon dates determines the age of an object containing organic material by using the properties of radiocarbon (also known as carbon-14), a radioactive isotope of carbon. Radiocarbon dating methods produce data based on the ratios of different carbon isotopes in a sample that must then be further manipulated in order to ...
The carbon-bearing gases were made with carbon-14 (14 C), a heavy, radioactive isotope of carbon. If there were photosynthetic organisms present, it was believed that they would incorporate some of the carbon as biomass through the process of carbon fixation, just as plants and cyanobacteria on earth do. After several days of incubation, the ...
This can be investigated with environmental isotopes, including 14 C. 14 C is predominantly produced in the upper atmosphere and from nuclear testing, with no major sources or sinks in the ocean. This 14 C from the atmosphere becomes oxidized into 14 CO 2, allowing it to enter the surface ocean through gas transfer. This is transferred into the ...