Properties of ionic compounds

• Ionic compounds


  Form giant ionic lattices
• Giant ionic lattice


  • Every positive ion is surrounded by negative ions
  • Every negative ion is surrounded by positive ions
  • Three-dimensional structure
• Electrostatic forces of attraction

  • Strong forces of attraction between positive and negative ions
  • Also called ionic bonds
  • Act in all directions
• Heating an ionic solid

  Particles vibrate with enough energy to break the electrostatic forces of attraction, causing the solid to melt
• Melting and boiling points of ionic compounds

  Very high due to the strong electrostatic forces of attraction requiring a great deal of heat energy to break
• Sodium chloride has a melting point of around 800°C
• Ionic compounds cannot conduct electricity when solids

  Ions are locked in place by strong electrostatic forces of attraction, can only vibrate but not move
• Ionic compounds can conduct electricity when molten or dissolved in water


  Ions can now move and carry the electrical charge
• When ionic compounds conduct electricity, it is the ions that are moving, not electrons