The oxidation state shown by silicon when it combines with strongly electropositive metals is

$Ge(II)$ compounds are strong reducing agents,whereas $Pb(IV)$ compounds are strong oxidizing agents. This is due to:

Dry ice is

The silicate having one monovalent corner oxygen atom in each $SiO_4$ tetrahedron unit is:

The catenation tendency of $C, Si$ and $Ge$ is in the order $Ge < Si < C$. The bond energies (in $kJ \ mol^{-1}$) of $C-C, Si-Si$ and $Ge-Ge$ bonds are respectively:

The last element of group-$14$ is found to be