1. Show the class pictures of five very different mammals, such as a cat, kangaroo, horse, rabbit, and monkey. Explain that all these animals are mammals, and that mammals constitute one class of the animal kingdom, which also includes other classes, such as reptiles, birds, and fish. Ask students what these five mammals have in common and mark their responses on a sheet of chart paper.
When ionic compounds are in a molten state or dissolved in water, forming an aqueous solution, the ions that formed the ionic compounds are able to move around freely, thus able to conduct electricity.
In solid ionic compounds, the ions are attracted to form a lattice and are unable to move freely and hence, they cannot conduct electricity. However, if you melt an ionic compound or dissolve it in water, these ions are now free to move around because the weak ionic bonds are now broken. The ions in these conditions are free to move and carry electrons between the anode and the cathode. As a result, the solution can be made to conduct electricity.