In group $13$ of the long form of the periodic table, an element $X$ has a boiling point of $T_2 \ (K)$ and a melting point of $T_1 \ (K)$. Identify the element $X$ for which $T_2 - T_1 \ (K)$ is maximum.

When borax is dissolved in water,it gives an alkaline solution. The alkaline solution consists of the following products:

Addition of mineral acid to an aqueous solution of Borax,the following compound is formed:

The correct Lewis acidity order of $BX_3$ is:

Write the preparation of diborane and describe its physical and chemical properties.

What are the correct statements about the elements of group $13$ given below?
$(I)$ The stability of $+1$ oxidation state follows the order $Tl > In > Ga$
$(II)$ Boron has the lowest melting point and boiling point as it is a non-metal
$(III)$ Boron shows a maximum covalency of $4$ in its compounds
$(IV)$ The order of atomic radius is $Ga > Al > In$
$(V)$ Aluminium is passive to concentrated nitric acid