Topic: Properties of Ionic Bonds Do Now: Get ready for Ionic Quiz

Structure of Ionic Compounds Ions are attracted to each other by strong electrostatic interactions (+/-) Ions form crystal lattice – regular 3-D pattern or array – Ions held in fixed positions (solid state) Unit Cell = smallest repetitive unit in lattice

lattice structure 

The more Na and Cl 2, the larger the resulting NaCl crystal -just keep adding on to it

Different representations of a crystal lattice

Properties of Ionic Compounds High melting points Low vapor pressures Solids do not conduct electricity –Ex: NaCl(s) doesn’t conduct electricity Molten state (liquid state) does conduct electricity –Ex: NaCl (l) does Solutions conduct electricity –Ex: NaCl (aq) does Tend to be hard and brittle These properties are due to the crystal lattice structure – strong electrostatic forces make it very hard to pull ions apart

Hard and Brittle Hard – due to the crystal lattice Brittle – when hit the ions shift and repel one another