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  2. Radiometric dating - Wikipedia

    en.wikipedia.org/wiki/Radiometric_dating

    D 0 is number of atoms of the daughter isotope in the original or initial composition, N(t) is number of atoms of the parent isotope in the sample at time t (the present), given by N(t) = N 0 e −λt, and; λ is the decay constant of the parent isotope, equal to the inverse of the radioactive half-life of the parent isotope [19] times the ...

  3. Isotopes in medicine - Wikipedia

    en.wikipedia.org/wiki/Isotopes_in_medicine

    A medical isotope is an isotope used in medicine. The first uses of isotopes in medicine were in radiopharmaceuticals , and this is still the most common use. However more recently, separated stable isotopes have come into use.

  4. Radioactivity in the life sciences - Wikipedia

    en.wikipedia.org/wiki/Radioactivity_in_the_life...

    In the case of the hydrogen isotope tritium (half-life = 12.3 years) and carbon-14 (half-life = 5,730 years), these isotopes derive their importance from all organic life containing hydrogen and carbon and therefore can be used to study countless living processes, reactions, and phenomena.

  5. Commonly used gamma-emitting isotopes - Wikipedia

    en.wikipedia.org/wiki/Commonly_used_gamma...

    With a short half-life of 8 days, this radioisotope is not of practical use in radioactive sources in industrial radiography or sensing. However, since iodine is a component of biological molecules such as thyroid hormones, iodine-131 is of great importance in nuclear medicine, and in medical and biological research as a radioactive tracer.

  6. Radionuclide - Wikipedia

    en.wikipedia.org/wiki/Radionuclide

    Radioactive nonprimordial, but naturally occurring on Earth. 61 347 Carbon-14 (and other isotopes generated by cosmic rays) and daughters of radioactive primordial elements, such as radium, polonium, etc. 41 of these have a half life of greater than one hour. Radioactive synthetic half-life ≥ 1.0 hour). Includes most useful radiotracers. 662 989

  7. Isotope-ratio mass spectrometry - Wikipedia

    en.wikipedia.org/wiki/Isotope-ratio_mass...

    Water molecules containing the common hydrogen isotope (and the common oxygen isotope, mass 16) have a mass of 18. Water incorporating a deuterium atom has a mass of 19, over 5% heavier. The energy to vaporise the heavy water molecule is higher than that to vaporize the normal water so isotope fractionation occurs during the process of evaporation.

  8. Uranium–uranium dating - Wikipedia

    en.wikipedia.org/wiki/Uranium–uranium_dating

    Uranium–uranium dating is a radiometric dating technique which compares two isotopes of uranium (U) in a sample: uranium-234 (234 U) and uranium-238 (238 U). It is one of several radiometric dating techniques exploiting the uranium radioactive decay series, in which 238 U undergoes 14 alpha and beta decay events on the way to the stable isotope 206 Pb.

  9. Iodine-123 - Wikipedia

    en.wikipedia.org/wiki/Iodine-123

    Iodine-123 (123 I) is a radioactive isotope of iodine used in nuclear medicine imaging, including single-photon emission computed tomography (SPECT) or SPECT/CT exams. The isotope's half-life is 13.2232 hours; [1] the decay by electron capture to tellurium-123 emits gamma radiation with a predominant energy of 159 keV (this is the gamma primarily used for imaging).