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Nitrogen-14 is the source of naturally-occurring, radioactive, carbon-14. Some kinds of cosmic radiation cause a nuclear reaction with nitrogen-14 in the upper atmosphere of the Earth, creating carbon-14, which decays back to nitrogen-14 with a half-life of 5700(30) years.
[citation needed] The 14 N (n,p) 14 C nuclear reaction is responsible for most of the radiation dose delivered to the human body by thermal neutrons – these thermal neutrons are absorbed by the nitrogen 14 N in proteins, causing a proton to be emitted; the emitted proton deposits its kinetic energy over a very short distance in the body ...
An example of cosmic ray spallation is a neutron hitting a nitrogen-14 nucleus in the Earth's atmosphere, yielding a proton, an alpha particle, and a beryllium-10 nucleus, which eventually decays to boron-10. Alternatively, a proton can hit oxygen-16, yielding two protons, a neutron, and again an alpha particle and a beryllium-10 nucleus.
[5] [12] These cosmic rays generate neutrons as they travel through the atmosphere which can strike nitrogen-14 (14 N) atoms and turn them into 14 C. [5] The following nuclear reaction is the main pathway by which 14 C is created: n + 14 7 N → 14 6 C + p. where n represents a neutron and p represents a proton. [13] [14] [note 3] Once produced ...
An example of electron emission (β − decay) is the decay of carbon-14 into nitrogen-14 with a half-life of about 5,730 years: 14 6 C → 14 7 N + e − + ν e. In this form of decay, the original element becomes a new chemical element in a process known as nuclear transmutation.
14 C is constantly formed from nitrogen-14 (14 N) in the upper atmosphere by cosmic rays which generate neutrons. These neutrons hit 14 N to produce 14 C which then combines with oxygen to form 14 CO 2. This radioactive CO 2 spreads through the lower atmosphere and the oceans where it is absorbed by plants, and animals that eat the plants.
Carbon-14, most frequently but not solely, generated by the neutron activation of atmospheric nitrogen-14 with a thermal neutron, is (together with its dominant natural production pathway from cosmic ray-air interactions and historical production from atmospheric nuclear testing) also generated in comparatively minute amounts inside many ...
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