In which of the following,a salt of the type $KMO_2$ is obtained?

For a $p$-block element,its $3d, 3s, 3p$ and $4s$ orbitals are completely filled and the differentiating electron goes to the $4p$ orbital. The element should have its atomic number in the range:

When borax is dissolved in water,it gives an alkaline solution. The alkaline solution consists of the following products:

Draw the structures of $BCl_3.NH_3$ and $AlCl_3$ (dimer).

Aqueous solution of which of the following boron compounds will be strongly basic in nature?

Boric acid is polymeric due to