- Ionic bonds are formed by one atom transferring electrons to another atom to form ions.
- Ions are atoms, or groups of atoms, which have lost or gained electrons.
- The atom losing electrons forms a positive ion (a cation) and is usually a metal.
- The atom gaining electrons forms a negative ion (an anion) and is usually a non-metallic element.
- Ions of opposite charge will attract one another by strong electrostatic force, thus creating an ionic bond.
- The ionic bond is also known as electrovalence bond.
Example: Ionic Bonding between Group 1 Metals and Group 17 Elements
- The figure above shows the illustration of the formation of the ionic bond between a sodium atom (group 1 metal) and a chlorine atom (group 17 element).
- The electron arrangement of the sodium atom is 2.8.1, which is not octet and hence not stable.
- To achieve octet electrons arrangement, the sodium atom donates/release one electron and form sodium ion.
- The electron arrangement of the chlorine atom is 2.8.7, which is also not octet and hence not stable, too.
- To achieve octet electrons arrangement, the chlorine atom receives one electron from the sodium atom and form a chloride ion.
- The sodium ion and the chloride ion carry opposite charges, hence they attract each other and form an ionic bond between each other.
Example: Ionic Bonding between Group 2 Metals and Group 17 Elements
- The figure above shows the illustration of the formation of the ionic bond between two potassium atoms (group 1 metal) and an oxygen atom (group 16 element).
- The electron arrangement of the potassium atom is 2.8.8.1, which is not octet and hence not stable.
- To achieve octet electrons arrangement, the potassium atom donates/release one electron and form potassium ion.
- The electron arrangement of oxygen atom is 2.6, which is also not octet and hence not stable, too.
- To achieve the octet electrons arrangement, the oxygen atom receives two electrons from potassium atoms and form an oxide ion.
- The potassium ions and the oxide ion carry opposite charges, hence they attract each other and form two ionic bond between the ions.
Example: Ionic Bonding between Group 2 Metals and Group 16 Elements
- The figure above shows the illustration of the formation of the ionic bond between a calcium atom (group 2 metal) and an oxygen atom (group 16 element).
- The electron arrangement of the calcium atom is 2.8.8.2, which is not octet and hence not stable.
- To achieve octet electrons arrangement, the potassium atom donates/release two electrons and form calcium ion.
- The electron arrangement of oxygen atom is 2.6, which is also not octet and hence not stable, too.
- To achieve the octet electrons arrangement, the oxygen atom receives two electrons from the calcium atom and form an oxide ion.
- The calcium ion and the oxide ion carry opposite charges, hence they attract each other and form an ionic bond between each other.
