Lesson Plan

• Describe the process of corrosion and its impact on metal structures.
• Explain how painting, greasing and plastic coating act as barrier methods.
• Compare the advantages and disadvantages of each barrier method.
• Select the most suitable barrier method for a given environment.
• Evaluate the effectiveness of a barrier method through observation and discussion.

• Projector and screen for slides.
• Whiteboard and markers.
• Sample metal pieces (e.g., iron nails).
• Small quantities of paint, grease, and a plastic coating material (or images).
• Worksheet with a comparison table.
• Diagram of barrier methods (handout or slide).

Begin with a quick question: “What everyday objects have you seen rust?” Use the responses to highlight the importance of protecting metals. Review the definition of corrosion and outline today’s success criteria – students will be able to name three barrier methods and explain when each is appropriate.

1. Do‑now (5'): Students list rust‑prone items; share answers; teacher writes success criteria.
2. Mini‑lecture (10'): Define corrosion, show the iron‑rust equation, discuss why protection is needed.
3. Demonstration (10'): Apply paint, grease, and a plastic coating to three metal samples; discuss how each creates a barrier.
4. Group activity (12'): Students complete the worksheet comparison table, noting advantages and disadvantages.
5. Whole‑class discussion (8'): Groups present findings; class decides the best method for different scenarios.
6. Exit ticket (5'): Each student writes one advantage of each barrier method.

Recap the key idea that barrier methods prevent the contact between metal, water and oxygen. Collect exit tickets to gauge understanding, and assign a short homework task: research a real‑world example where one of these methods is used and explain why it was chosen.