Lesson Plan

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Lesson Plan
Grade: Date: 04/03/2026
Subject: Chemistry
Lesson Topic: Identify physical and chemical changes, and describe the differences between them
Learning Objective/s:
  • Identify whether a change observed in a demonstration is physical or chemical.
  • Explain the key differences in definition, reversibility, and energy changes between physical and chemical changes.
  • Apply a checklist to classify given examples and justify the classification with observable evidence.
Materials Needed:
  • Projector and screen for slides
  • Whiteboard and markers
  • Worksheets with practice examples
  • Samples: ice, candle, salt, water, hydrochloric acid, sodium hydroxide, glass bottle, iron nails
  • Safety goggles and lab aprons
  • Checklist handout
 Introduction:
Begin with a quick demonstration of ice melting and a candle burning to spark curiosity about visible changes. Ask students what they already know about changes in matter and how they decide if a change is merely physical or involves a new substance. Explain that today they will learn criteria to distinguish the two and will be able to justify their decisions.
Lesson Structure:
  1. Do‑Now (5’) – Students list examples of changes they have seen today and label them as physical or chemical.
  2. Mini‑lecture (10’) – Define physical and chemical changes, highlight key differences with the comparison table projected.
  3. Demonstration (10’) – Show ice melting, candle burning, and mixing acid‑base while students note observable evidence.
  4. Guided practice (12’) – In pairs, students use the checklist handout to classify a set of examples on the worksheet, discussing reasoning.
  5. Whole‑class discussion (8’) – Review answers, correct misconceptions, and reinforce the checklist criteria.
  6. Exit ticket (5’) – Each student writes one physical and one chemical change with the evidence that supports each classification.
Conclusion:
Summarise that physical changes alter form or state without new substances, whereas chemical changes produce new substances and are often irreversible. Remind students to use the checklist as a quick decision tool. Collect exit tickets and assign a short homework: classify five everyday observations as physical or chemical, providing justification.