The electronic configuration of four elements is : 

 $\left(\mathrm{i}\right) \mathrm{W} = 2,6 \left(\mathrm{ii}\right) \mathrm{X} = 2,8 \left(\mathrm{iii}\right) \mathrm{Y} = 2,8,1 \left(\mathrm{iv}\right) \mathrm{Z} = 2,8,7$

Which pair of atoms will form a covalent compound ?

Give a reason for the following:

Ionic compounds have a high melting point.

Two elements $\mathrm{A}$ and $\mathrm{B}$ have electronegativities $1.2$ and $3.0$ respectively. The nature of bond between $\mathrm{A}$ and $\mathrm{B}$ would be

Find out the correct order of ionic character in the following molecules

$\left(\mathrm{i}\right) {\mathrm{SO}}_2$     $\left(\mathrm{ii}\right) {\mathrm{K}}_2\mathrm{O}$     $\left(\mathrm{iii}\right) {\mathrm{N}}_2$    $\left(\mathrm{iv}\right) \mathrm{LiF}$