Before students can grasp the idea of bonding, they must first be familiar with the concept of valence electrons, or those electrons in the outer shell of an atom. A quick way for students to identify valence electrons is to have them draw electron dot configurations for common elements. As they draw these diagrams, they should notice whether it will be easier for a given element to gain or lose electrons to conform to the octet rule.
Once students understand valence electrons, they should become familiar with the number of bonds a given element can form. To do this, give each student a tag bearing an element name. The card should also list the oxidation number of the element. Students should then "bond" with other students based on these numbers. Explain that the non-metallic elements will often bond with other elements like themselves. For example, chlorine atoms will bond with other chlorine atoms, while forming covalent bonds.
Another way to show both covalent and ionic bonding is through the use of different colors of marshmallows and candies. Have students create cards naming the elements and listing the number of valence electrons each has. Models of these elements and their valence electrons can then be recreated using marshmallows and skittles. Let the marshmallows represent the element while different colored skittles recreate the electrons. Ask students to show the different types of bonding using these materials.
Once students are familiar with the properties of elements that form ionic and covalent bonds, it's time to put their knowledge to work. First, ask students what kind of tests they could perform to determine the type of bonding. Then divide the class into groups, giving each group a list of properties of a given compound. Based on the list, ask students to determine whether ionic or covalent bonding is present.