An analogy of baking a cake is used to explain the terms reactants and products in a chemical reaction. Until the cake is baked in the oven, it's just a mixture of the ingredients. After cooking the ingredients become chemically altered to form new products.
Continuing the theme of cooking and food, students could conduct a card sort, in which they divide a series of food preparation processes into those that involve chemical reactions and those that just mix ingredients together. The class could them discuss any similarities that suggest the reactions have things in common. As a practical exercise, the different effect of heat on chocolate and egg white could be used as a starting point for discussion on physical and chemical change and on reversible and non-reversible reactions.