Which of the following structures is similar to graphite?

Which of the following properties describes the diagonal relationship between boron and silicon?

The structure of $Na_2[B_4O_5(OH)_4] \cdot 8H_2O$ contains:

The formula of an oxyacid of phosphorus is $H_3PO_4$. It is a

Which of the following compounds exhibits acidic nature?

Identify the correct sets:
$i$. Boron fibres - bullet proof vest
$ii$. Metal borides - protective shields
$iii$. Borax - glass wool
Correct option is