Boric acid,$H_3BO_3$,is a/an ....

In diborane $(B_2H_6)$, the number of electrons that accounts for bonding in the bridges is

Give reasons: Aluminium alloys are used to make aircraft bodies.

Which of the following compounds of boron is the hardest?

Identify the $P$ and $Q$ of the following reaction: $P + Q \longrightarrow [B(OH)_4]^{-} + H_3O^{+}$

Assertion $(A)$: $[B(OH_2)_6]^{3+}$ and $[B(OH)_4]^{-}$ form octahedral and tetrahedral structures.
Reason $(R)$: Being electron deficient, boron readily reacts with Lewis bases like $H_2O$ and $OH^{-}$.
The correct option among the following is