General Characteristics of the Group 4A Elements

The group 4A elements possess the outer-shell electron configuration ns np. The electronegativities of the elements are generally low (V TABLE 22.8) carbides that formally contain C ions are observed only in the case of a few compounds of carbon with ver)y active metals. Formation of 4-1- ions by electron loss is not observed for any of these elements the ionization energies are too high. The +2 oxidation state is found in the 

What limits the range of temperatures you can use for zone refining of silicon  

As heating coil slowly moves down, impurities concentrate in molten section, leaving behind ultrapure Si 

A FIGURE 22.33 Zone-refining apparatus for production of ultrapure silicon. 

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