Creating Models of Chemical Reactions

Creating models of chemical reactions is super important to help students understand how things change and how atoms balance. In this activity, students will create a grid that illustrates four chemical reactions. They should be sure to include the reactants, products, and the equation in their finished product. To extend this activity, ask students to add a cell that explains what type of reaction it is (exothermic vs endothermic) and what happens during the process.

The chemical reaction models suggested below get more difficult as students progress through. The final two reactions listed in the activity require students to use the additional skill of balancing the symbol equation with coefficients. If you want to avoid this, choose the following alternative reactions:

• Reaction between sodium and water to produce sodium hydroxide and hydrogen - Na + H₂O → NaOH + H₂
• Reaction of sulfur trioxide and water to form sulfuric acid - SO₃ + H₂O → H₂SO₄

Example Chemical Reactions

• Iron and Sulfur: Exothermic reaction that forms iron sulfide. The word equation for this reaction is iron + sulfur → iron sulfide. The balanced symbol equation is Fe + S → FeS.
• Hydrogen and Oxygen: Reaction that forms water. The word equation for this reaction is hydrogen + oxygen → water. The balanced symbol equation is 2H₂ + O₂ → 2H₂O
• Methane and Oxygen: Combustion that forms carbon dioxide and water. The balanced symbol equation is CH₄ + 2O₂ → CO₂ + 2H₂O. This reaction requires students to balance the equation.
• Photosynthesis: Endothermic reaction that produces glucose and oxygen. The word equation for photosynthesis is carbon dioxide + water → glucose + oxygen. The balanced symbol equation is 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂. This reaction requires students to balance the equation.

Student Instructions

Model various chemical reactions by creating a T-Chart on Storyboard That. Identify the reactants and products in the reactions and create models of the molecules. Remember: atoms are not created or destroyed in a chemical reaction, so the total number of atoms doesn’t change.

1. Click "Start Assignment".
2. Identify the products and reactants of the following:
   • Reaction between Iron and Sulfur
   • Combustion of Hydrogen in Air
   • Combustion of Methane in Air
   • Photosynthesis
3. Write the names of the reactants and products in the title of cell.
4. Write the symbols in the description box underneath.
5. Add coefficients if necessary to balance the symbol equation.
6. Use shapes to model the arrangement of the different atoms for the reactants and products.
7. Count the number of each type of atom before and after the reaction to ensure your symbol equation is correctly balanced.