Covalent bonding

Covalent bonding is the type of bonding done between non-metal atoms only. There is no transfer of electrons in covalent bonding because the electrons are shared. The electrons shared are valence electrons (electrons in the outer shell) which results in a complete outer shell for each atom involved.

Where “e” represent Electrons

A single covalent bond is a shared pair of electrons. As can be seen above, the Hydrogen atom shares its single electron with chlorine. If we count all of chlorine’s outer electron, including the shared electrons, we will see that it now possesses 8 electrons and has a complete outer shell resembling the closest Nobel gas, Argon.

If we count all the outer electrons for Hydrogen, we will see that it now has 2 electrons. This is a complete outer shell as it now resembles the closest
Nobel gas in Helium. We should always bear in mind that all elements try to acquire the electronic configuration of the closest Nobel gas.

Another example of covalent bonding is the bonding that occurs between 2 oxygen atoms to form the diatomic oxygen molecule. Diatomic gases are gases whose molecules are made of two atoms. Oxygen forms a diatomic molecule to achieve stability. Oxygen and most other elemental gases are found as a diatomic molecule naturally. Oxygen possesses 6 electrons in its outer shell and needs two more electrons to complete its outer electron shell. As such each oxygen atom will share 2 of its electrons to form a double bond . A double bond is 2 pairs of electrsons or 4 electrons – 2 from each atom. If we count the outer electrons of each oxygen atom, including the shared electrons, we will see that there are a total of eight (8) electrons. This is a complete outer shell. An example of this is shown below:

Where “e” is used to represent electrons