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  2. Potassium-40 - Wikipedia

    en.wikipedia.org/wiki/Potassium-40

    Potassium-42 has a short half life of just over half a day, so exposure to it is usually through the air, but it cannot accumulate in longer lived plants or animals. Potassium-42 is produced by the natural decay of argon-42 with a half-life time of 32.9 years. Argon-42 is in turn produced mostly from nuclear reactions between highly energetic ...

  3. Isotopes of potassium - Wikipedia

    en.wikipedia.org/wiki/Isotopes_of_potassium

    K decay per second. [4] The decay of 40 K to 40 Ar is used in potassium-argon dating of rocks. Minerals are dated by measurement of the concentration of potassium and the amount of radiogenic 40 Ar that has accumulated. Typically, the method assumes that the rocks contained no argon at the time of formation and all subsequent radiogenic argon ...

  4. Decay scheme - Wikipedia

    en.wikipedia.org/wiki/Decay_scheme

    The decay scheme of a radioactive substance is a graphical presentation of all the transitions occurring in a decay, and of their relationships. Examples are shown below. It is useful to think of the decay scheme as placed in a coordinate system, where the vertical axis is energy, increasing from bottom to top, and the horizontal axis is the proton number, increasing from left to right.

  5. Beta decay - Wikipedia

    en.wikipedia.org/wiki/Beta_decay

    The two types of beta decay are known as beta minus and beta plus.In beta minus (β −) decay, a neutron is converted to a proton, and the process creates an electron and an electron antineutrino; while in beta plus (β +) decay, a proton is converted to a neutron and the process creates a positron and an electron neutrino. β + decay is also known as positron emission.

  6. K–Ar dating - Wikipedia

    en.wikipedia.org/wiki/K–Ar_dating

    Potassium–argon dating, abbreviated K–Ar dating, is a radiometric dating method used in geochronology and archaeology. It is based on the measurement of the product of the radioactive decay of an isotope of potassium (K) into argon (Ar). Potassium is a common element in many materials, such as feldspars, micas, clay minerals, tephra, and ...

  7. Positron emission - Wikipedia

    en.wikipedia.org/wiki/Positron_emission

    This rare form of potassium makes up only 0.012% of the element on Earth and has a 1 in 100,000 chance of decaying via positron emission. Positron emission should not be confused with electron emission or beta minus decay (β − decay), which occurs when a neutron turns into a proton and the nucleus emits an electron and an antineutrino.

  8. K–Ca dating - Wikipedia

    en.wikipedia.org/wiki/K–Ca_dating

    Potassium–calcium dating, abbreviated K–Ca dating, is a radiometric dating method used in geochronology. It is based upon measuring the ratio of a parent isotope of potassium (40 K) to a daughter isotope of calcium (40 Ca). [1] This form of radioactive decay is accomplished through beta decay. Calcium is common in many minerals, with 40

  9. List of Feynman diagrams - Wikipedia

    en.wikipedia.org/wiki/List_of_Feynman_diagrams

    Beta decay: beta particle is emitted from an atomic nucleus Compton scattering: scattering of a photon by a charged particle Neutrino-less double beta decay: If neutrinos are Majorana fermions (that is, their own antiparticle), Neutrino-less double beta decay is possible. Several experiments are searching for this. Pair production and annihilation