Which of the following element$(s)$ exist in the liquid state?

$A$ 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.

Give important trends and anomalous properties of boron.

The acidic strength of boron trihalides follows the order:

The incorrect statement from the following for borazine is:

Boron can be obtained by various methods but not by