Boron does not form $B^{3+}$ cation easily. It is due to

Explain the following:
$(1)$ $BF_3$ does not hydrolyze.
$(2)$ Why does the element silicon not form a graphite-like structure,whereas carbon does?

Which of the following is the weakest acid?

In the reaction $B(OH)_{3} + 2 H_{2}O \rightarrow [B(OH)_{4}]^{-} + H_{3}O^{+}$,$B(OH)_{3}$ functions as:

Which of the following halides of group $13$ elements is the most acidic?

$A$ certain salt $X$ gives the following results:
$(i)$ Its aqueous solution is alkaline to litmus.
$(ii)$ It swells up to a glassy material $Y$ on strong heating.
$(iii)$ When conc. $H_2SO_4$ is added to a hot solution of $X$,white crystals of an acid $Z$ separate out.
Identify $X, Y$ and $Z$ and write the equations for the reactions.