$AlCl_3$ in water at $pH < 7$ forms

Identify the incorrect pair from the following:

Aluminium reacts with $NaOH$ and forms compound '$X$'. If the coordination number of aluminium in '$X$' is $6$, the correct formula of $X$ is:

Match List-$I$ with List-$II$:

List-$I$	List-$II$
$a$. Borax	$i$. $NaBO_2$
$b$. Kernite	$ii$. $Na_2B_4O_7 \cdot 4H_2O$
$c$. Orthoboric acid	$iii$. $H_3BO_3$
$d$. Borax bead	$iv$. $Na_2B_4O_7 \cdot 10H_2O$

Choose the correct answer from the options given below:

Given below are two statements:
Statement $I$: Boron is extremely hard,indicating its high lattice energy.
Statement $II$: Boron has the highest melting and boiling point compared to its other group members.
In the light of the above statements,choose the most appropriate answer from the options given below:

The bonding in diborane $(B_2H_6)$ can be described by