Radon isotopes

Rn-220 is another isotope of radon and belongs to the thorium decay series. Due to its short half life of 55.6 s, reports on its concentrations in those gases and in natural water are still scant. They are also important for a better estimate of our exposure to natural radioactivity and also for the geochemical study of the forma tion of those radon isotopes and their underground movement. 

Table I. Properties of the Naturally Occurring Radon Isotopes and Their Major Decay Products...

Alpha emitting radionuclides — including nadium-226+228, but excluding radon isotopes... 

When radium (A = 88) emits an alpha particle, its atomic number reduces by 2 and becomes the new element radon (A = 86). The resulting atomic mass is reduced by 4. If th e radium was of the most common isotope, 226, then the radon isotope would have atomic mass number 222. 

The radioactive decay of the three radon isotopes after they are produced can be shown as follows ... 

Within a year of the discovery of XePtFe and as a result of worldwide activity, it was clear that the chemistry of the noble gases would be limited to the heavier elements as set out in my Noranda Lecture (see Ref. S2). Because of the dangerous radioactivity associated with all of the radon isotopes, this meant that the bulk of noble-gas chemistry would be that of xenon. The chemistry of krypton appeared to be limited to KrF2 and compounds that could be derived from it. In all cases, it was clear, the range of accessible noble-gas chemistry was dictated by lower ionization potentials at the noble-gas atom, and high electronegativity and small size of the ligand atoms, as discussed in Ref. 45. 

There is a radon isotope in each of the three major namral-decay chains ( Rn, half-... 

All isotopes of radon have short half-lives and do not remain in the atmosphere very long. The half life of a radioactive element or isotope is the time it takes for half of a sample of the element or isotope to break down. The radon isotope with the longest half life is radon-222 at only 3.8235 days. If 10 grams of radon-222 were prepared today, only 5 grams would remain 3.8235 days from now. After another 3.8235 days, only 2.5 grams would be left. Within a month, it would be difficult to detect any of the isotope. 

The half-life of one radon isotope is 3.8 days. If a sample of gas contains 4.38 g of radon-222, how much radon will remain in the sample after 15.2 days ... 

Radioactive Rn and °Rn form constantly from the decay of uranium and thorium in rocks and soil and, being gaseous, seep out of the ground. The radon isotopes decay fairly quickly, but their products, which are also radioactive, are then in the air and attach themselves to dust particles. Thus, airborne radioactivity can accumulate to worrisome levels in poorly ventilated basements in ground that is rich in uranium and thorium. 

Can alpha decay alone explain the formation of these radon isotopes from and Th If not, state what other types of decay must occur. 

Advective flux measurements can be conducted using seepage meter, piezometer, dye tracers, and radium or radon isotopes. 

Alpha-emitting radionuclides -including radium- 226, -228, but excluding radon isotopes 0.555 Bq(15pCi)/L... 

Emanometric methods are radioanalytical methods that use measurement of radioactive isotopes of inert gases for the determination of appropriate elements. A good example is the use of the radon isotopes Rn, Rn, and Rn to determine radon, thorium, radium, and actinium. Indirect determinations... 

It would be difficult to design a radionuclide with characteristics more suitable for easy separation and determination than Rn. A noble gas with no stable compounds, it can be readily separated from the myriad of solid radionuclides and the other radon isotopes disappear rapidly by decay. 

The amounts of radon isotopes in the environment depend primarily upon the concentrations of... 

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