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In this technique, one or more of the atoms of the molecule of interest is substituted for an atom of the same chemical element, but of a different isotope (like a radioactive isotope used in radioactive tracing). Because the labeled atom has the same number of protons, it will behave in almost exactly the same way as its unlabeled counterpart ...
A radioactive tracer, radiotracer, or radioactive label is a synthetic derivative of a natural compound in which one or more atoms have been replaced by a radionuclide (a radioactive atom). By virtue of its radioactive decay , it can be used to explore the mechanism of chemical reactions by tracing the path that the radioisotope follows from ...
Due to pre-calibration and efficiency issues this number is never seen on a label; the values often found are 800, 3000 and 6000 Ci/mmol. With this number it is possible to calculate the total chemical concentration and the hot-to-cold ratio. "Calibration date" is the date in which the vial's activity is the same as on the label.
Monoisotopic elements are characterized, except in one case, by odd numbers of protons (odd Z), and even numbers of neutrons. Because of the energy gain from nuclear pairing, the odd number of protons imparts instability to isotopes of an odd Z , which in heavier elements requires a completely paired set of neutrons to offset this tendency into ...
[8] [9] When a chemical symbol is used, e.g. "C" for carbon, standard notation (now known as "AZE notation" because A is the mass number, Z the atomic number, and E for element) is to indicate the mass number (number of nucleons) with a superscript at the upper left of the chemical symbol and to indicate the atomic number with a subscript at ...
Radiochemistry is the chemistry of radioactive materials, where radioactive isotopes of elements are used to study the properties and chemical reactions of non-radioactive isotopes (often within radiochemistry the absence of radioactivity leads to a substance being described as being inactive as the isotopes are stable).
Different oxygen isotopic signatures can indicate the origin of material ejected into space. [41] The Moon's titanium isotope ratio ( 50 Ti/ 47 Ti) appears close to the Earth's (within 4 ppm). [ 42 ] [ 43 ] In 2013, a study was released that indicated water in lunar magma was 'indistinguishable' from carbonaceous chondrites and nearly the same ...
Phosphorus is abundant in biological systems and, as a radioactive isotope, is almost chemically identical with stable isotopes of the same element. Phosphorus-32 can be used to label biological molecules. The beta radiation emitted by the phosphorus-32 is sufficiently penetrating to be detected outside the organism or tissue which is being ...