a) Igniting a match is a chemical change, as the products of the reaction were different from the reactants themselves. Since new substances were formed, lighting a match represents a chemical change. b) Many pieces of evidence show that this reaction is a chemical change. First, striking a match almost immediately produces light and odor in the form of fire and smoke respectively. Also, as the fire burns, the temperature of the match increases due to the heat from the fire. Finally, the lighting of a match cannot be undone, making it a definite chemical change. c) The head of a match contains potassium chlorate, sulfur, and powdered glass. The striking surface consists of sand, powdered glass, and red phosphorus. In striking a match, the sand