Intermediate types of binary compound

The three types of binary compound that we have been considering are what we have called limiting types . In other words they represent extremes, and most binary compounds fall somewhere in between these extremes. 

As can be seen from the following diagram, there are four intermediate types, corresponding to the one intermediate type between metallic and nonmetallic elements  

The properties of the intermediate t) es can be inferred from the properties of the limiting types. 

Type A High transparency, no lustre, weak electrolytic conductivity in fused state. 

Type B High opacity, possibly some lustre, semiconducting in solid and liquid. 

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Between these limiting types are bonds of intermediate character, corresponding to the intermediate types of binary compound ... 

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