Alkaline earth metals Group sources

The alkali metals (Group 1A) and the alkaline earth metals (Group 2A) are not found free in nature because they are so easily oxidized. Their primary sources are seawater, brines of their soluble salts and deposits of sea salt. The metals are obtained from the electrolysis of their molten salts. 

Like the alkali metals, the Group IIA elements occur in nature as silicate rocks. They also occur as carbonates and sulfates, and many of these are commercial sources of alkaline earth metals and compounds. 

The elements of the second row also differ from their heavier congeners. Lithium is anomalous among the alkali metals and resembles magnesium more than its congeners. In turn, in Group 11A (2) beryllium is more clo.sely akin to aluminum than to the other alkaline earths. The source of this effect is discussed below. We have already. ecn that fluorine has been termed a superhalogen on the basis of its differences from the remainder of Group VllA (17). 

A 140-page summary report describing the behavior of fission products in the MSRE is the most complete source of information on fission product behavior in molten fluorides. In all instances, the evidence confirms what basic thermodynamics tells us only the noble gases (Xe, Kr) and tritium are released from the salt. All of the alkali (eg., Cs), alkaline earth (e.g., SrX rare earth (e.g., Y, Ln), and most metallic fission products (e g., Zr) are dissolved in the salt as fluorides and are relatively nonvolatile. A few of the metallic fission products (the noble group Ag, Pd, Ru, Mo, Tc, Rh, Sb) are not dissolved (or are partially dissolved), but remain as metallic species and tend to deposit on the colder metallic surfaces. 

The acetylides of alkali metals and salts of alkaline earths are reactive compounds, which violently decompose in contact with water or even in contact with moisture in the air, releasing acetylene. These acetylides do not have the characteristics of primary explosives and are widely used in organic synthesis as a source of the acetylene (ethyn-l,2-diyl) group. 

Alkaline earth and REfluoroalkoxides ([M(OR) ], where M = metal elements and OR = fluoroalkoxo groups) were examined as precursors for metal fluorides in the sol-gel process (Poncelet, 1998 Chi, 2002). Such fluoroalkoxides were prepared by the reaction of polyether-substituted flouroalcohols with metal source reagents, Sr(OC3H7)2 orBaH2. It was possible to obtain pure metal fluoride powders by hydrolysis or pyrolysis of the precursors. 

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