Bromine radioactive isotopes

The halogens will be restricted to chlorine, bromine and iodine since fluorine, as the most electronegative element, does not function as the central atom in a complex and astatine has only short-lived, radioactive isotopes, so that very little of its coordination chemistry has been investigated.2 ... 

It is evident from Table 1 that certain limiting factors exist. For example, experiments with bromine-82 are limited to a duration of about one week because of the short half-life. At the other end of the scale, experiments with stable carbon-13 are limited to dilutions of less than x 500. Even with radioactive isotopes the maximum specific activity available may limit dilution though not to the same extent. Thus, chlorine-36 can stand dilutions up to x 107 but tritium can improve on this to a factor of x 1012. 

A variety of radioactive isotopes is available having gamma rays diller-ing in penetrating ability, and with half-lives varying from a few minutes to many years. Radioactive iodine with an 8 day half-life and radioactive bromine with a l -day half-life were used for most tests. Radiation from these isotopes passes easily through the walls of pipe found in the oil field. 

The method is only directly applicable to solids which have an element with a radioactive isotope. Kolthoff and O Brien1 used artificially radioactive bromine for estimating the surface of silver bromide it is necessary, here, to have an adsorbed layer of dyestuff, to restrict exchange with the interior. In the case of lead salts the areas deduced by the radioactive method are of the same order of magnitude as those found by microscopic examination the discrepancies may, however, reach 100 or 200 per cent. 

Thirty-four radioactive isotopes of bromine are known also. A radioactive isotope is one that breaks apart and gives off some form of radiation. Radioactive isotopes are produced when very small particles are... 

As with DOI, the presence of a heavy atom, the bromine atom, in DOB makes the radioactive isotope labelled material a powerful research tool. Studies with DOB labelled with either 82Br or 77Br have been used in human subjects to follow the distribution of the drug. The use of a whole body scanner permits the imaging of the intact body, with the travelings of the radioactivity easily followed from outside. 

ISOTOPES There are a total of 40 isotopes of bromine. Of these, only two are stable Br-79 constitutes 50.69% of the stable bromine found on Earth, and Br-81 makes up 49.31% of the naturally occurring abundance. All the other isotopes of bromine are radioactive with half-lives ranging from 1.2 nanoseconds to 16.2 hours. 

Several chlorine isotopes exist with mass numbers ranging between 32 and 40. The two stable isotopes are Cl and Cl with natural abundances of 75.77% and 24.23% respectively, while the others are radioactive. Bromine also has two stable isotopes, Br and Br, with natural abundances of 50.69% and 49.31% respectively, while the others are radioactive. Iodine has only one stable isotope, and numerous radioactive ones are known. Astatine is known only as its radioisotope see Radioactive Decay). 

A second software feature capitalizes on the fact that many potential drug candidates contain atoms that are not naturally occurring in the body and which possess unique isotopic patterns. In particular, chlorine and bromine atoms give unique and distinctive mass spectral signals. The computer can evaluate the sample dataset and find any chromatographic peaks that contain these characteristic isotopic patterns. An example of how these software routines can simplify a complex chromatogram is shown in Fig. 2. This compound contained a tritium label, so the top trace (A) shows peaks corresponding to radioactive metabolites. The second... 

Astatine is a member of the halogen family, elements in Group 17 (VlIA) of the periodic table. It is one of the rarest elements in the universe. Scientists believe that no more than 25 grams exist on Earth s surface. All isotopes of astatine are radioactive and decay into other elements. For this reason, the element s properties are difficult to study. What is known is that it has properties similar to those of the other halogens—fluorine, chlorine, bromine, and iodine. Because it is so rare, it has essentially... 

PROBLEM 6.14 The mass 82 isotope of bromine ( Br) is radioactive and is used as a tracer to identify the origin and destination of individual atoms in chemical reactions and biological transformations. A sample of 1,1,2-tribromocyclohexane was prepared by adding Br— Br to ordinary (nonradioactive) 1-bromocyclo-hexene. How many of the bromine atoms in the 1,1,2-tribromocyclohexane produced are radioactive Which ones are they ... 

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