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  2. Carbon-12 - Wikipedia

    en.wikipedia.org/wiki/Carbon-12

    Carbon-12 (12 C) is the most abundant of the two stable isotopes of carbon (carbon-13 being the other), amounting to 98.93% of element carbon on Earth; [1] its abundance is due to the triple-alpha process by which it is created in stars.

  3. Isotopes of carbon - Wikipedia

    en.wikipedia.org/wiki/Isotopes_of_carbon

    Carbon (6 C) has 14 known isotopes, from 8 C to 20 C as well as 22 C, of which 12 C and 13 C are stable.The longest-lived radioisotope is 14 C, with a half-life of 5.70(3) × 10 3 years. . This is also the only carbon radioisotope found in nature, as trace quantities are formed cosmogenically by the reactio

  4. Carbon - Wikipedia

    en.wikipedia.org/wiki/Carbon

    Carbon makes up about 0.025 percent of Earth's crust. [14] Three isotopes occur naturally, 12 C and 13 C being stable, while 14 C is a radionuclide, decaying with a half-life of 5,700 years. [15] Carbon is one of the few elements known since antiquity. [16]

  5. Table of nuclides - Wikipedia

    en.wikipedia.org/wiki/Table_of_nuclides

    A chart or table of nuclides maps the nuclear, or radioactive, behavior of nuclides, as it distinguishes the isotopes of an element.It contrasts with a periodic table, which only maps their chemical behavior, since isotopes (nuclides that are variants of the same element) do not differ chemically to any significant degree, with the exception of hydrogen.

  6. Biological carbon fixation - Wikipedia

    en.wikipedia.org/wiki/Biological_carbon_fixation

    This is known as carbon isotope discrimination and results in carbon-12 to carbon-13 ratios in the plant that are higher than in the free air. Measurement of this isotopic ratio is important in the evaluation of water use efficiency in plants, [ 32 ] [ 33 ] [ 34 ] and also in assessing the possible or likely sources of carbon in global carbon ...

  7. Carbon group - Wikipedia

    en.wikipedia.org/wiki/Carbon_group

    There are 15 known isotopes of carbon. Of these, three are naturally occurring. The most common is stable carbon-12, followed by stable carbon-13. [13] Carbon-14 is a natural radioactive isotope with a half-life of 5,730 years. [18] 23 isotopes of silicon have been discovered. Five of these are naturally occurring.

  8. Valley of stability - Wikipedia

    en.wikipedia.org/wiki/Valley_of_stability

    Isotopes with the atomic number of the fission products and an N/Z near that of uranium or other fissionable nuclei have too many neutrons to be stable; this neutron excess is why multiple free neutrons but no free protons are usually emitted in the fission process, and it is also why many fission product nuclei undergo a long chain of β − ...

  9. Chemical element - Wikipedia

    en.wikipedia.org/wiki/Chemical_element

    All carbon atoms have 6 protons, but they can have either 6, 7, or 8 neutrons. Since the mass numbers of these are 12, 13 and 14 respectively, said three isotopes are known as carbon-12, carbon-13, and carbon-14 (12 C, 13 C, and 14 C). Natural carbon is a mixture of 12 C (about 98.9%), 13 C (about 1.1%) and about 1 atom per trillion of 14 C.