Differentiation Modifications Use the optional 5.3 More About Chemical Energy Reading as an optional step with more advanced students. Have students make an independent list of things that burn and things that don’t burn before the whole class discussion. Try burning other materials such as sugar, wood, and salt to support a more general discussion of why some materials burn and others do not. Tips Make sure that students notice that materials can be classified either on the basis of observable properties (organic materials include foods, fuels, bodies of plants and animals) or properties of molecules (organic materials have C-C or C-H bonds). Extending the Learning Have students classify other materials as organic or inorganic. Many materials (e.g., soil, soup, meat) are mixtures of organic and inorganic substances, but students should be able to classify the substances as organic or inorganic. Have students research cement and limestone to determine if they are organic or inorganic.