Because their ions are free to move from place to place. Ionic compounds cannot conduct electricity when solid, as their ions are held in fixed positions and cannot move.
Ok the answers to the hole .doc is
1. Neutrons, Protons, and Electrons
2. N<span>ucleus
3. N</span>eutrons and Protons
4. Electrons
5. Because they represent different things (I would put this in your own words)