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.
1 Electrical conductivity of the compound in aqueous solution. 2  Ionic compounds conduct electricity when dissolved in water, because the dissociated ions can carry charge through the solution. 3  Molecular compounds don't dissociate into ions and so don't conduct electricity in solution. Electrical conductivity of the compound in liquid form. 2  Ionic compounds conduct electricity well when melted; metallic solids do as well. 3  Covalent molecular compounds do not, because they usually don't transfer electrons unless they react.