Explain the following with suitable examples:
$(v)$ $12-16$ and $13-15$ group compounds.

(N/A) $(v)$ $12-16$ and $13-15$ group compounds: The $12-16$ group compounds are prepared by combining group $12$ and group $16$ elements,and the $13-15$ group compounds are prepared by combining group $13$ and group $15$ elements.
These compounds are prepared to simulate the average valence of $4$,as seen in $Ge$ or $Si$.
$13-15$ group compounds: Examples include indium $(III)$ antimonide $(InSb)$,aluminium phosphide $(AlP)$,and gallium arsenide $(GaAs)$. $GaAs$ semiconductors have a very fast response time and have revolutionised the design of semiconductor devices.
$12-16$ group compounds: Examples include zinc sulphide $(ZnS)$,cadmium sulphide $(CdS)$,cadmium selenide $(CdSe)$,and mercury $(II)$ telluride $(HgTe)$.
The bonds in these compounds are not perfectly covalent; the ionic character of the bonds depends on the electronegativities of the two elements.