Ionic compounds

• • An ionic compound is a giant structure of ion
• • Ionic compounds have a giant ionic lattice structure
  • The ions closely form regular lattice arrangement and are held by strong electrostatic forces between oppositely charged ions
  • The forces act in all directions
• • Dot and cross diagrams do not show the structure of a compound, the size of the ions or how they are arranged
• • Three dimensional models only lets you see the outer layer of the compound
• • The ball and stick model is not to scale, so the sizes of the ions are not showm
  • In reality, there are not gaps between the ions
• • they have high melting and boiling points because electrostatic forces are strong
  • a lot of energy is needed to overcome attraction
• • when ionic compounds are solid, the ions are in fixed positions, so cannot conduct electricity
  • when ionic compounds melt or dissolve in water , ions seperate and are free to move, so can carry electric charge