The alloy formed from aluminum is ............ .

The correct order of melting points of $Al$,$Ga$,$In$ is

$A$ compound $X$,of boron reacts with $NH_3$ on heating to give another compound $Y$,which is called inorganic benzene. The compound $X$ can be prepared by treating $BF_3$ with lithium aluminium hydride. The compounds $X$ and $Y$ are represented by the formulas.

Boron forms $BX_3$ type of halides. The correct increasing order of Lewis-acid strength of these halides is

Two elements $X$ and $Y$ combine separately with a highly electropositive metal to form binary compounds,which upon hydrolysis yield borane and silane,respectively. What are $X$ and $Y$?

Boric acid is not used in which of the following?