Draw the atomic orbit structure diagram for formation of -

(a) hydrogen molecule

(b) chlorine molecule

(c) oxygen molecule

(d) nitrogen molecule

[at. no. H=1, Cl=17, O=8, N=7]

Give reasons for formation of single covalent bond between two chlorine atoms and a double covalent bond between two oxygen atoms - during formation of respective covalent molecules.

With the help of an atomic orbit structure diagram - explain the formation of :

(a) carbon tetrachloride

(b) methane

[at. no. : C=6, Cl=17, H=1]

Explain the formation of a radical from a covalent bond with an example.