Ionic Compounds

• An ionic compound is a giant structure of electrons.
• Ionic compounds are held together by strong electrostatic forces of attraction between the oppositely charged ions. These forces act in all directions in the lattice and this is called ionic bonding
• Ionic compounds have a structure called a giant ionic lattice
• The ions form a closely packed regular lattice arrangement and there are very strong electrostatic forces of attraction between two oppositely charged ions, in all directions within the lattice
• A single crystal of sodium chloride (table salt) is a giant ionic lattice
• Ionic compounds all have similar properties

  • high melting and boiling points
  • when they're solid, ions are held in place, so compounds can't conduct electricity. when they melt, ions are free to move and they'll carry electric current
  • some dissolve in water. the ions separate and are all free to move in the solution, so they'll carry electric current
• to work out the empirical formula using a dot and cross diagram, count up how many atoms there are of each element and write it down to give you the empirical formula
• to work out the empirical formula using a 3D diagram, use it to work out WHAT ions are in the ionic compound, then balance out the charges of the ions so that the overall charge of the compound is 0