The common basic structural unit in silicates and silica is

When graphite is heated at $300^{\circ} C$ with potassium vapour, it forms $C_8K$ compound that shows one of the following property.

The order of catenation property for $C, Si,$ and $Ge$ is $Ge < Si < C$. What will be the bond dissociation energy (in $kJ \ mol^{-1}$) for $C-C, Si-Si,$ and $Ge-Ge$ bonds respectively?

$P_4O_{10}$ has short and long $P-O$ bonds. The number of short $P-O$ bonds in this compound is

Among the following,the correct statements are:
$I$. Germanium exists only in traces.
$II$. $PbF_4$ molecule is tetrahedral in shape.
$III$. $GeX_2$ is more stable than $GeX_4$.

Which of the following is not a monomer for a high molecular mass silicone polymer?