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Systems and Scale | Activity 4.4

Activity 4.4: Molecular Models for Ethanol Burning (50 min)

Students model the combustion of ethanol (C2H5OH) to carbon dioxide and water using molecular model kits. They describe this chemical change in two ways: molecular models, and a chemical equation.

Materials You Provide

  • molecular model kit (1 per pair of students)
  • scissors (1 per pair of students)
  • twist ties (at least 12 per pair of students)

Resources Provided

Recurring Resources


Prepare one model kit, one Molecular Models 11 x 17 Placemat
, one pair of scissors, and one Forms of Energy Cards for each pair of students. Print one copy of the 4.4 Molecular Models for Ethanol Burning Worksheet and 4.4 A Tool for Explaining: Molecular Modeling Reading for each pair of students. Prepare a computer and a projector to display the PPT.


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


Listen for the students’ sense of necessity to make sure that atoms last forever during chemical changes. Asking them about the “atoms are forever” rule during the molecular modeling and animation may give you a sense of how committed they are to conserving matter.