Match the following reactions in Column-$1$ with their main products in Column-$2$.

Column-$1$ (Reaction)	Column-$2$ (Main product)
$A$. $B_2H_6 + 2CO \longrightarrow$	$I$. $B_2O_3$
$B$. $B_2H_6 + 3O_2 \longrightarrow$	$II$. $2BH_3 \cdot CO$
$C$. $B_2H_6 + 6H_2O \longrightarrow$	$III$. $2H_3BO_3$

The correct match is:

Which compound is not a monobasic acid?

The stability of $+1$ oxidation state among $Al$,$Ga$,$In$ and $Tl$ increases in the sequence:

Match the following:

List-$I$ (Group $13$ element)	List-$II$ (Metallic radius,$pm$)
$A$. $Al$	$I$. $135$
$B$. $Ga$	$II$. $143$
$C$. $In$	$III$. $170$
$D$. $Tl$	$IV$. $167$

The correct answer is:

Borax,on being heated strongly above its melting point,melts to a liquid and then solidifies to a transparent mass commonly known as a Borax Bead. This transparent glassy mass consists of:

Aluminum dissolves in mineral acids and aqueous alkalis and thus shows amphoteric character. $A$ piece of aluminum foil is treated with dilute hydrochloric acid or dilute sodium hydroxide solution in a test tube and on bringing a burning match stick near the mouth of the test tube,a pop sound indicates the evolution of hydrogen gas. The same activity when performed with concentrated nitric acid,the reaction does not proceed. Explain the reason.