Silicon is an important constituent of which of the following?

Which of the following is the most stable?

Which of the following is/are ionic in nature?
$(i)$ $GeF_4$ $(ii)$ $SnF_4$ $(iii)$ $PbF_4$

The stability of dihalides of $Si, Ge, Sn$ and $Pb$ follows the sequence.

The tendency of catenation in group-$14$ elements follows the order:

The silicate anion in the mineral kinoite is a chain of three $SiO_4$ tetrahedra,that share corners with adjacent tetrahedra. The charge of the silicate anion is