Isotopes

Isotopes C화학적 특성, 용도, 생산

정의

Two or more species of the same element differing in their mass numbers because of differing numbers of neutrons in their nuclei. The nuclei must have the same number of protons (an element is characterized by its proton number). Isotopes of the same element have very similar properties because they have the same electron configuration, but differ slightly in their physical properties. An unstable isotope is termed a radioactive isotope or radioisotope
Isotopes of elements are useful in chemistry for studies of the mechanisms of chemical reactions. A standard technique is to label one of the atoms in a molecule by using an isotope of the element. It is then possible to trace the way in which this atom behaves throughout the course of the reaction. For example, in the esterification reaction:
ROH + R′COOH≒H2O + R′COOR it is possible to find which bonds are broken by using a labeled oxygen atom. If the reaction is performed using ¹⁸O in the alcohol it is found that this nuclide appears in the ester, showing that the C–OH bond of the acid is broken in the reaction. In labeling, radioisotopes are detected by counters; stable isotopes can also be used, and detected by a mass spectrum.
Isotopes are also used in kinetic studies. For example, if the bond between two atoms X–Y is broken in the rate-determining step, and Y is replaced by a heavier isotope of the element, Y*, then the reaction rate will be slightly lower with the Y* present. This kinetic isotope effect is particularly noticeable with hydrogen and deuterium compounds, because of the large relative difference in mass.

Pharmaceutical Applications

Atoms of the same element can have different numbers of neutrons; the different possible versions of each element are called isotopes.

Isotopes 준비 용품 및 원자재

원자재

준비 용품

Isotopes 공급 업체

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