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.
Ionic compounds have a high melting and boiling point, whereas covalent compounds have a comparatively lower melting and boiling point. The reason for this fact, is that ionic compounds require a huge amount of energy to break their ionic bonds, and pull apart the positive and negative charges.