$Na_2B_4O_7$ $\xrightarrow{x} H_3BO_3$ $\xrightarrow{\Delta} B_2O_3$ $\xrightarrow{y} B$
Here $X$ and $Y$ are respectively:

Consider the compounds,$BCl_3$ and $CCl_4$. How will they behave with water? Justify.

Substance $X$ reacts with an aqueous solution of $NaOH$ to form $Y$ and releases $H_2$ gas. When an aqueous solution of $Y$ is heated at $323 \; K - 333 \; K$ and $CO_2$ gas is passed through it,it yields $Al_2O_3 \cdot xH_2O$ (often represented as $Al(OH)_3$) and $Z$. Heating $Z$ at $1200^{\circ}C$ produces $Al_2O_3$. Identify $X, Y,$ and $Z$.

Borax in its crystal structure possesses:

The number of three-centre two-electron $(3c-2e)$ bonds in a molecule of diborane $(B_2H_6)$ is

Boron fluoride exists as $BF_3$ but boron hydride does not exist as $BH_3$. Give reason. In which form does it exist? Explain its structure.