Isotope vs. nuclide. A nuclide is a species of an atom with a specific number of protons and neutrons in the nucleus, for example carbon-13 with 6 protons and 7 neutrons. The nuclide concept (referring to individual nuclear species) emphasizes nuclear properties over chemical properties, whereas the isotope concept (grouping all atoms of each element) emphasizes …

Geschichte, physikalische Eigenschaften. Isotope, Natürliche Häufigkeitem, Halbwertszeiten, Zerfälle und deren Wahrscheinlichkeit. Sehr übersichtlich. The Lund/LBNL Nuclear Data Search (englisch) vom Department of Physics der Lund University (Schweden) und dem LBNL der UCB (USA) Stand 1999, etliche Cross-Reference-Seiten funktionieren nicht ...

Background. The kinetic isotope effect is considered to be one of the most essential and sensitive tools for the study of reaction mechanisms, the knowledge of which allows the improvement of the desirable qualities of the corresponding reactions.For example, kinetic isotope effects can be used to reveal whether a nucleophilic substitution reaction follows a …

The isotope-ratio mass spectrometer (IRMS) allows the precise measurement of mixtures of naturally occurring isotopes. Most instruments used for precise determination of isotope ratios are of the magnetic sector type. This type of analyzer is superior to the quadrupole type in this field of research for two reasons. First, it can be set up for multiple-collector analysis, and …

Als Isotope (von altgriechisch ἴσος ísos „gleich“ und τόπος tópos „Ort, Stelle“) bezeichnet man Atomarten, deren Atomkerne gleich viele Protonen, aber unterschiedlich viele Neutronen enthalten. Sie haben dieselbe Ordnungszahl, stellen daher dasselbe Element dar, weisen aber verschiedene Massenzahlen auf; es gibt also Sauerstoffisotope, Eisenisotope usw.

Helium-3 (3 He see also helion) is a light, stable isotope of helium with two protons and one neutron (the most common isotope, helium-4, having two protons and two neutrons in contrast).Other than protium (ordinary hydrogen), helium-3 is the only stable isotope of any element with more protons than neutrons. Helium-3 was discovered in 1939. ...

Uranium (92 U) is a naturally occurring radioactive element that has no stable isotope.It has two primordial isotopes, uranium-238 and uranium-235, that have long half-lives and are found in appreciable quantity in the Earth's crust.The decay product uranium-234 is also found. Other isotopes such as uranium-233 have been produced in breeder reactors.

Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written 235 U) has been increased through the process of isotope separation.Naturally occurring uranium is composed of three major isotopes: uranium-238 (238 U with 99.2739–99.2752% natural abundance), uranium-235 (235 U, 0.7198–0.7202%), and uranium-234 (234 U, …

Marine isotope stages (MIS), marine oxygen-isotope stages, or oxygen isotope stages (OIS), are alternating warm and cool periods in the Earth's paleoclimate, deduced from oxygen isotope data reflecting changes in temperature derived from data from deep sea core samples.Working backwards from the present, which is MIS 1 in the scale, stages with even numbers have high …

T, or t, is the twentieth letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide.Its name in English is tee (pronounced / ˈ t iː /), plural tees. It is derived from the Semitic Taw ???? of the Phoenician and Paleo-Hebrew script (Aramaic and Hebrew Taw ת/????/, Syriac Taw ܬ, and Arabic ت Tāʼ) via the …