BEHAVIOR OF THE NOBLE GASES

Although the partitioning behavior of the noble gases between minerals and melts is... 

There have been various ideas regarding the relative behaviors of the noble gases. 

The apparently inert chemical behavior of the noble gases (s p configuration) gave the original and sustaining support to the theoretical significance of the stable electronic octet. The octet concept, however, conditioned subsequent generations of chemists to believe that these... 

For solutions of gases in organic solvents, the situation is often the reverse of that just described that is, gases may become more soluble at higher temperatures. The solubility behavior of the noble gases in water is more complex. The solubility of each gas decreases with an increase in temperature, reaching a... 

An alternative approach to the formation of true chemical compounds of the nohlc gases is suggested by two lines of thought. (1) From an acid-base point of view, the strongest Lewis acid is the bare proton. H. so ir anv of the noble gases is capable of exhibiting basic behavior it might be expected to do so with H ( / H,0 ) ... 

The periodic trends in main-group elements become apparent when we compare the binary compounds they form with one specific element. All the main-group elements, with the exception of the noble gases and, possibly, indium and thallium, form binary compounds with hydrogen, so these hydrides can be examined to look for periodic trends. We meet the binary hydrides several times in this chapter and the next, so, at this stage, we confine the discussion to a brief survey and see how their properties reveal periodic behavior. 

All solubility calculations to date assume ideal gas behavior for the noble gases irrespective of geological environment. At near surface conditions, Lewis-Randall mixing is a reasonable assumption. It is clear from Figure 2, that the assumption of ideal behavior for He, Ne, and Ar at near surface conditions is also reasonable. More care must be taken with Kr and Xe, where deviation from ideality at 300-m depth is -6% and -15% respectively. Taking a linear extrapolation from 300-m depth to the surface (and ideal conditions) for example, would suggest that at 30-m depth Kr and Xe show -0.6% and -1.5% deviation from ideality. Solubility calculations for moderate depth hydrostatic... 

A detailed treatment of noble gas behavior relevant to geochemistry and cosmochemistry is given by Ozima and Podosek (2001). A brief review is provided here only to set out some of the more commonly required data and to outline the nature of the processes that control the variations in the relative elemental abundances and isotopic compositions of the noble gases. Some basic elemental data are shown in Table 7. 

Which of the noble gases other than radon would you expect to depart most readily from ideal behavior Use the density data in Table 7.8 to show evidence in support of your answer. 

With the sole exception of the noble gases, during reactor normal operation as well as in the course of reactor accidents, all the fission products are subjected to chemical reactions which govern their transport and behavior. These reactions have to be taken into account, therefore, when the release of fission products in anticipated accidents is calculated. However, chemical reactions and physical phenomena to be expected under the conditions of reactor accidents, as well as the resulting products, are only accessible for theoretical calculations in a very global manner. For this reason, experiments are needed at least to validate the theoretical results or, in many cases, to get an idea on the possible reaction mechanisms. The planning and performance of such experiments and the interpretation of the results obtained will pose some problems which have to be taken into consideration before the work is begun. 

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