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Systems and Scale | Activity 5.3

Activity 5.3: Preparing for Future Units – Organic vs. Inorganic (40 min)

Students “zoom in” to ethanol, wood, and water to distinguish between organic materials (materials with high-energy C-C and C-H bonds) and inorganic materials (materials with other chemical bonds).

Materials you Provide

Resources Provided


Print one copy of 5.3 Materials Cards for each pair of students and cut the cards out ahead of time. Print one copy of 5.3 Organic vs. Inorganic Worksheet
per student. If you plan on using the optional  (1 per student)
, print one handout for each student.


1. Use the instructional model to show students where they are in the course of the unit.

Show slide 2 of the 5.3 Organic vs. Inorganic PPT.


Listen to students’ responses to the question: why does ethanol burn like wood, even though it looks like water? Check to see whether some students are moving beyond labeling materials as “flammable” to thinking about chemical properties of flammable materials. Do any students mention chemical energy? Do any students mention C-C and C-H bonds? Note students' ability to identify organic materials based on observable properties; organic materials include foods, fuels, and bodies of plants and animals, and based on molecular formulas: organic molecules have C-C and/or C-H bonds.

Use 5.3 Grading the Organic vs. Inorganic Worksheet to grade student responses. At this point, students can be held accountable for correct answers. If students are still struggling with these concepts, you may want to revisit parts of the lesson they are finding difficult.


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).


  • 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.

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.