• The formation of the covalent bond only happens when both of the atoms combined are non-metals.
• The elements in group 14, 15, 16, 17 are non-metals.
• The formation of the covalent bond can happen either between the same or different atoms.
• The covalent bond is formed from the sharing of electrons.
• There are three types of covalent bond;
  • Single bond: one pair of electrons shared between two atoms.
  • Double bond: two pairs of electrons shared between two atoms.
  • Triple bond: three pairs of electrons shared between two atoms.

Formation of Single Covalent Bond

• The formation of a covalent bond happens when the electrons were shared between the atoms.
• A single covalent bond is formed when a pair of electrons being shared.
• The sharing of electrons is to make sure the atoms are able to reach the stable duplet or octet electron arrangement.
• Below shows how the formation of the single covalent bond between 2 atoms.

Electron arrangement of water, \(H_2O\)

Formation of Double Covalent Bond

• The double covalent bond is formed when the two non-metal atoms are combined, in order to reach the stable octet electron arrangement.
• A double covalent bond means two pairs of electrons are shared between the atoms.
• Usually, the atoms that form double bonds has 6 valence electrons.
• Below shows the formation of a double covalent bond between two oxygen atoms.

Electron arrangement of oxygen gas, \(O_2\)