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Properties of ionic compound

Atoms Molecules Ions Chemical Equations On-line practice


  1. The ions in an ionic crystal are held together by strong ionic bonds or electrostatic forces of attraction.
  2. A large amount of heat is needed to break these strong bonds, so a very high temperature is required.  Therefore, ionic compounds have high melting and boiling points.
  3. The melting points of ionic compounds depend on the strength of their ionic bonds.  The bigger the charges of the positive and negative ions, the stronger are the ionic bonds and the higher the melting point.
  4. Ionic compounds do not conduct electricity when solid. 
  5. When they are heated strongly, they melt at a high temperature.  The molten compound then conducts electricity.
  6. Ionic compounds also conduct electricity when they dissolve in water.  This is because the ions can move in the molten state or when dissolved in water.
  7. It is the moving ions that carry the electric current.  In the solid state, the ions cannot move, so the current cannot flow. 


Formation of ionic compound ] Formation of covalent compound ]