low-abundance isotope

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• Isotope-ratio mass spectrometry — Isotope ratio mass spectrometer with gas bench in foreground Acronym IRMS Classification mass spectrometry Other techniques …   Wikipedia

• isotope — isotopic /uy seuh top ik/, adj. isotopically, adv. /uy seuh tohp /, n. Chem. any of two or more forms of a chemical element, having the same number of protons in the nucleus, or the same atomic number, but having different numbers of neutrons in… …   Universalium

• Abundance of the chemical elements — Estimated proportions of matter, dark matter and dark energy in the universe. Only the fraction of the mass and energy in the universe labeled atoms is composed of chemical elements. The abundance of a chemical element measures how relatively… …   Wikipedia

• Natural abundance — In chemistry, natural abundance (NA) refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass (a weighted average) of these isotopes is the atomic weight listed for the element in the… …   Wikipedia

• Oxygen isotope ratio cycle — Oxygen isotope ratio cycles are cyclical variations in the ratio of the abundance of oxygen with an atomic mass of 18 to the abundance of oxygen with an atomic mass of 16 present in some substances, such as polar ice or calcite in ocean core… …   Wikipedia

• mass spectrometry — or mass spectroscopy Analytic technique by which chemical substances are identified by sorting gaseous ions by mass using electric and magnetic fields. A mass spectrometer uses electrical means to detect the sorted ions, while a mass spectrograph …   Universalium

• dating — I In geology and archaeology, the process of determining an object s or event s place within a chronological scheme. Scientists may use either relative dating, in which items are sequenced on the basis of stratigraphic clues (see stratigraphy) or …   Universalium

• chemical element — Introduction also called  element,         any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which all matter is composed.       This article considers the… …   Universalium

• Actinide — The atomic bomb dropped on Nagasaki had a plutonium charge.[1] The actinide or actinoid (IUPAC nomenclature) series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium thro …   Wikipedia

• Nuclear magnetic resonance — This article is about the physical phenomenon. For its use as a method in spectroscopy, see Nuclear magnetic resonance spectroscopy. NMR redirects here. For other uses, see NMR (disambiguation). First 1 GHz NMR Spectrometer (1000 MHz,… …   Wikipedia

• Xenon — (PronEng|ˈzɛnɒn [Xenon, entry in the Oxford English Dictionary, prepared by J. A. Simpson and E. S. C. Weiner, vol. 20, second edition, Oxford: Clarendon Press, 1989. ISBN 0 19 861232 X (vol. 20), ISBN 0 19 861186 2 (set.)] or IPAlink en|ˈziːnɒn… …   Wikipedia