Q. Explain the structure of Single covalent bonds?

Ans.

Atoms tend to achieve the stable electron configuration of a noble gas when forming a bond. In covalent bonding this is done by electron sharing.

Here are the electron dot diagrams for the hydrogen (H₂) and chlorine (Cl₂) molecules:

The electron dot structure for the hydrogen molecule shows how the two hydrogen atoms share their electrons to achieve the electron structure of helium. Note the electron pair that is being shared.

Similarly, two chlorine atoms can each share one unpaired electron from their outermost shells. A shared electron pair results. Note in the diagram that both chlorine atoms now have an octet of electrons. Therefore, each chlorine has now become like the noble gas argon.