Below are two statements, one labeled as Assertion $(A)$ and the other as Reason $(R):$

Assertion $(A)$: Among group $13$ elements, boron's melting point is unusually high $(2453 \mathrm{~K})$.

Reason $(R):$ Solid boron has a strong crystalline lattice.

In the context of the above statements, choose the correct answer from the following options:

Identify the correct statement for $B _{2} H _{6}$ from those given below.

$(A)$ In $B _{2} H _{6}$, all $B – H$ bonds are equivalent.

$(B)$ In $B _{2} H _{6}$ there are four $3-$centre$-2-$electron bonds.

$(C)$ $B _{2} H _{6}$ is a Lewis acid.

$(D)$ $B _{2} H _{6}$ can be synthesized form both $BF _{3}$ and $NaBH _{4}$.

$(E)$ $B _{2} H _{6}$ is a planar molecule.

Choose the most appropriate answer from the options given below….. .

The correct formula of borax is

What happens when

$(a)$ Borax is heated strongly,

$(b)$ Boric acid is added to water,

$(c)$ Aluminium is treated with dilute $NaOH$,

$(d)$ $BF_3$ is reacted with ammonia?

Write balanced equations for : 

$(i)\,B{F_3} + LiH \to $

$(ii)\,{B_2}{H_6} + {H_2}O \to $

$(iii)\,NaH + {B_2}{H_6} \to $

$(iv)\,{H_3}B{O_3}\xrightarrow{\Delta }$

$(v)\,Al + NaOH \to $

$(vi)\,{B_2}{H_6} + N{H_3} \to $