Find the non-semiconductor element among the following.

Bleaching powder is obtained by the action of chlorine on which of the following?

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

In which of the following silicates,only two corners per tetrahedron are shared?
$I$. Pyro silicate
$II$. Cyclic silicate
$III$. Double chain silicate
$IV$. Single chain silicate
$V$. $3D$ silicate
$VI$. Sheet silicate

The three elements $X$,$Y$ and $Z$ with electronic configurations shown below all form hydrides:

Element	Electronic configuration
$X$	$1s^2, 2s^2, 2p^2$
$Y$	$1s^2, 2s^2, 2p^6, 3s^1$
$Z$	$1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 3d^{10}, 4s^2, 4p^5$

Which set of properties match correctly with properties of the hydrides of these elements?

$[SiF_6]^{2-}$ is known whereas $[SiCl_6]^{2-}$ is not. Give possible reasons.