Which of the following halides is the most stable?

Assertion $(A): [SiF_6]^{2-}$ is formed but $[SiCl_6]^{2-}$ is not.
Reason $(R):$ Electronegativity $(EN)$ of $F$ is higher than $EN$ of $Cl$.

Explain the following:
$(1)$ $Tl(NO_3)_3$ acts as an oxidizing agent.
$(2)$ Carbon shows catenation property but lead does not.

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?

The number of non-ionisable protons present in the product $B$ obtained from the following reaction is:
$3C_{2}H_{5}OH + PCl_{3} \rightarrow 3C_{2}H_{5}Cl + H_{3}PO_{3} (A)$
$H_{3}PO_{3} + PCl_{3} \rightarrow H_{4}P_{2}O_{5} (B) + HCl$

In the carbon family,which of the following statements is true as the atomic number increases?