Question

N2,HCL,O2,H2O which among the above molecules do not show polar nature? give reason

Answer 1

Answer. Nitrogen, oxygen molecules doesn't show polar nature.

Explanation. in order to check whether molecule's  is polar or non polar nature we look for dipole moment in the the molecule.

Dipole moment is define as measure of overall polarity of the molecule present due to unequal sharing of electrons.

In $N_{2}$, both atoms with same electronegativities are present and thus they  possess no polar nature.

 In  $O_{2}$, both atoms with same electronegativities are present and thus they  possess no polar nature.                                                                      

in HCl , the atoms hydrogen and chlorine have different electronegativities resulting into partial negative charge on chlorine and partial positive charge on hydrogen thus resulting into polarity.                                                        

In $H_{2}O$molecule, the atoms hydrogen and oxygen have different electronegativities resulting into partial negative charge on oxygen and partial positive charge on hydrogen thus resulting into polarity. The presence of lone pairs of electrons on oxygen further enhance the polarity. as shown in the image below.