Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Physics
Lesson Topic: Know that the random motion of microscopic particles in a suspension is evidence for the kinetic particle model of matter
Learning Objective/s:
  • Describe the kinetic particle model and its description of solids, liquids and gases.
  • Explain how Brownian motion provides visual evidence for the model.
  • Analyse the influence of temperature and viscosity on the observed motion.
  • Apply the concept to answer typical exam‑style questions.
Materials Needed:
  • Low‑power microscope
  • Slides with a suspension (milk or fine chalk particles)
  • Beakers and water
  • Projector and screen
  • Worksheet with guided questions
  • Whiteboard and markers
 Introduction:
Begin with a short video of pollen grains jittering under a microscope to capture interest. Ask students what could cause particles to move in a still fluid, linking to prior learning about kinetic energy of molecules. Explain that today they will investigate this phenomenon as evidence for the kinetic particle model and will be able to describe and explain the observations.
Lesson Structure:
  1. Do‑now (5'): Students write a quick definition of the kinetic particle model on mini‑whiteboards.
  2. Mini‑lecture (10'): Review states of matter and introduce Brownian motion with a diagram.
  3. Demonstration (15'): Teacher shows the milk suspension under the microscope; students record observations on the worksheet.
  4. Guided analysis (10'): Discuss how collisions with invisible molecules cause the motion; relate to temperature and viscosity.
  5. Practice questions (10'): Pairs answer three exam‑style questions while teacher circulates.
  6. Summary check (5'): Whole‑class recap using a quick poll or exit ticket.
Conclusion:
Summarise that the random jitter of suspended particles confirms the constant motion of unseen molecules predicted by the kinetic model. Ask students to write one key takeaway on an exit ticket. Assign a short homework task: research another historical observation that supported the kinetic theory.