The general formula of the compounds formed when group $13$ elements $(A)$ react with group $16$ elements $(B)$ is

In the following reaction,assign the nature of the product formed by the complete hydrolysis of the underlined atom at $R.T.$:
$H_4\underline{P}_2O_5 + H_2O \longrightarrow \text{Products}$

Boron is unable to form $BF_{6}^{3-}$ ion. Explain.

Boric acid is not used in which of the following?

Which of the following shows dimerisation?

Choose the incorrect statement/reaction.