Mercury nuclides

Here on Earth, spallation facilities are being built, not just to produce specific nuclides, but to provide a source of neutrons. Typically, a lead or mercury target... 

With a few exceptions, the use of metallic mercury in medicine is considered to be outdated the few exceptions include its use in certain preservatives and in dental amalgam. The radioactive nuclides Hg and ° Hg have been used diagnostically, but the amount of mercury involved is very small. Even the mercury thermometer is rapidly being replaced by safer alternative devices. The use of mercury in dermatological therapy should be abandoned because of the risk of mercury intoxication (1). 

Radioactivity and Toxicity. Table III lists the radionuclides in aged waste, their half-lives, the expected radioactivity of each after 10 years aging, and the relative toxicity of each. Relative toxicity is defined as the ratio of the concentration of a given isotope to its maximum permissible concentration in public zone water. Mercury, nitrate, and nitrite (although not radioactive) are also listed because their toxicity is actually greater than that of many of the radioactive nuclides. Sr and Cs are... 

To make the subscripts balance in our equation, the subscript for the missing nuclide must be 80, indicating that the symbol for the produa nuclide should be Hg, for mercury. The mass number stays the same in beta emission, so we write... 

Mercury-197 was used in the past for brain scans. Its decay can be detected, because this nuclide undergoes electron capture, which forms an excited atom that then releases a gamma photon that escapes the body and strikes a detector. Write the nuclear equation for the electron capture by mercury-197. 

The use of NMR spectroscopy to characterize diamagnetic transition metal and posttransition metal complexes has increased tremendously in the past decade (111, 129). Mercury has two NMR-active isotopes, Hg (natural abundance = 13.22%) and (natural abundance = 16.84%). The former is quadrupolar (nuclear spin, / = ), and consequently, much more difficult to observe, due to line broadening. The latter, on the other hand, is one of approximately 20 nuclides in the periodic table with the preferred spin I = i. Its receptivity, a measure of relative signal strength, is five times that of C for comparison, " Cd, the most widely studied of the posttransition nuclei, has a receptivity of only 8 relative to C. Magnetic resonance frequencies are intimately connected with the quantity and dis-... 

Which of the following nuclides would you expect to be radioactive 26pe, 27C0,4iNb, mercury-202, radium-226 Justify your choices. 

Transmutation is the conversion of one element into another by either natural or artificial means. Transmutation occurs spontaneously in natural radioactive disintegrations. Alchemists tried for centuries to convert lead and mercury into gold by artificial means, but transmutation by artificial means was not achieved until 1919, when Ernest Rutherford succeeded in bombarding the nuclei of nitrogen atoms with alpha particles and produced oxygen nuclides and protons. The nuclear equation for this transmutation can be written as... 

Figure 5.3 Ratio of nuclide mass functions jiij = m - mf) as a function of the discrimination exponent (n) for selected isotopes of mercury. Adapted from [17],...

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