Thermite Spheres

Two rusty iron spheres wrapped in aluminum foil are struck together to initiate a redox reaction. The reaction releases energy in the form of a popping noise and sparks, demonstrating the principles of thermite chemistry in a controlled and safe way.

1. Obtain two rusty iron spheres.
2. Strike the spheres together without foil to show that no reaction occurs.
3. Wrap both spheres with a layer of aluminum foil.
4. Strike the foil-wrapped spheres together firmly.
5. Observe the loud popping sound and sparks, especially visible in a darkened room.
6. Inspect the spheres to show that rust has been reduced to iron and the aluminum has been oxidized.

Microscale Thermite Reactione - Harvard Natural Sciences Lecture Demonstratrions:

📄 (Safe) Thermite Reaction (On page 5) - Author: https://www.unco.edu/nhs/science/pdf/demos/2005_CSC.pdf

• Use different degrees of rust on the spheres to see if reaction intensity changes.
• Compare the reaction with a true thermite mixture (iron oxide + aluminum powder) for students at an advanced level.

• Safety glasses and gloves must be worn at all times.
• Perform away from flammable materials.
• Do not allow students to strike the spheres themselves; only an instructor should handle them.
• Ensure that spectators are kept at a safe distance.

• What is being reduced and what is being oxidized in this reaction?
• Why does aluminum replace iron in the reaction?
• How does this “safe thermite” compare to a traditional thermite reaction in terms of energy release?
• Why is rust (iron oxide) required for the reaction to occur?
• What does the spark and popping sound reveal about the energy released during the reaction?