Ionic Compounds

• Ionic compounds are formed when electrons are transferred from metal to non metal atoms. This happens when metals react with non metals. This is called ionic bonding
• Dot and cross diagrams show the arrangement of electrons in an atom on ion. They can also show what happens to electrons when atoms react with each other. Each electron is represented by a dot or a cross
• Brackets must always surround drawings of ionic structures
• Ionic compounds have a regular lattice structure. The ions form a closely packed regular lattice . They have very strong electrostatic forces of attraction between oppositely charged ions, in all directions
• Sodium chloride (salt) is one giant ionic lattice. The positive sodium and negative chloride ions are held together by strong electrostatic forces.

  A) chlorine

  B) sodium

  
• Ionic compounds have high melting and boiling points due to strong attractions between the ions. It takes large amounts of energy to overcome this attraction
• Solid ionic compounds dont conduct electricity because the ions are in a fixed place and cannot move. But when an ionic compound melts, ions are free to move and carry an electric charge
• Many ionic compounds dissolve easily in water. The ions separate and are all free to move in the solution, so they carry an electric charge
• Ionic compounds have high melting and boiling points, because the bonds are strong in ionic compounds, therefore a lot of energy is needed to break them