Boron halides are Lewis acids because.....

In diborane,the $H-B-H$ bond angle is $120^o$. The hybridization of boron is likely to be

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

When borax is heated with $CoO$ on a platinum loop,the blue coloured bead formed is largely due to

Which of the following show diagonal relationship?

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Boron is unable to form $BF_{6}^{3-}$.
Reason $R$: Size of $B$ is very small.
In the light of the above statements,choose the correct answer from the options given below.