Free 4th Grade Chemical Reaction Lesson Plan (Science)

Topic: Chemical Reactions: The Effect of Heat on Marshmallows and Popcorn

Objectives & Outcomes

• Students will be able to observe the effects of heat on marshmallows and popcorn.

Materials

• Microwave
• Marshmallows
• Popcorn
• Timer
• Scales (optional)
• Balance (optional)

Warm-Up

• Ask the students if they have ever heated up food in the microwave before.
• Ask them to describe what they saw happen to the food.
• Discuss the concept of chemical reactions and how they can be caused by heat and/or agitation.

Direct Instruction

• Show the students the marshmallow and the popcorn.
• Explain that these are examples of materials that can undergo a chemical reaction when they are heated.
• Explain that when these materials are heated, they react with each other to form new substances.
• Ask the students to think about how they might expect the marshmallow and popcorn to change when they are heated.
• Have a student heat up the marshmallow and popcorn in the microwave for 5-10 seconds.
• While the students are waiting for the marshmallow and popcorn to cool down, ask them to predict what they think will happen to the materials.
• Once the materials have cooled down, have the students observe what happened to them and compare their predictions to what actually happened.

Guided Practice

• Have the students work in pairs to heat up another marshmallow and piece of popcorn in the microwave.
• While the students are working, walk around the room and provide support and guidance as needed.
• After a few seconds, have the students stop the microwave and observe the materials again.
• Ask the students to explain what they see and why they think it happened.

Independent Practice

• Have the students conduct a more thorough experiment to test the effects of different heating times on marshmallows and popcorn.
• For example, the students could heat a marshmallow and piece of popcorn for 5 seconds, then 20 seconds, then 50 seconds, and so on.
• After each heating time, have the students stop the microwave and observe the materials.
• Ask the students to write down their observations and make any inferences about the effects of heating time on the marshmallows and popcorn.

Closure

• Have the students share their observations and inferences with the class.
• Ask the students to summarize what they have learned about the chemical reactions that occur when marshmallows and popcorn are heated in the microwave.

Assessment

• Observe the students during the independent practice activity and use the observations to assess their understanding of the concept of chemical reaction.
• Collect and review the students' written reports for understanding of the concept of chemical reaction and the ability to apply their knowledge in analyzing and explaining a chemical reaction.