The hardest substance amongst the following is
$B{e_2}C$
Graphite
Titanium
${B_4}C$
The species, having bond angles of $120^o $ is
Which of the following mineral does not contain aluminium?
Purification of aluminium done by electrolytic refining is known as
Compare $\pi - $ bond strength between $B$ and $N$ given in two compounds
$(I)$ $\begin{array}{*{20}{c}}
{{{\left( {C{H_3}} \right)}_3}Si - NB{H_2}}\\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|}\\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,Si{{(C{H_3})}_3}}
\end{array}$ $(II)$ $\begin{array}{*{20}{c}}
{{{\left( {C{H_3}} \right)}_3}C - NB{H_2}}\\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|}\\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,C{{(C{H_3})}_3}}
\end{array}$
The function of fluorspar in the electrolytic reduction of alumina dissolved in fused cryolite $(N{a_3}Al{F_6})$ is