Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Chemistry
Lesson Topic: Describe changes of state in terms of melting, boiling, evaporating, freezing and condensing
Learning Objective/s:
  • Describe each change of state (melting, freezing, boiling, evaporation, condensation) and the associated energy flow.
  • Explain why melting/freezing and boiling/condensation occur at specific temperatures.
  • Distinguish between boiling and evaporation in terms of where vapour forms.
  • Interpret exam‑style questions and draw accurate particle diagrams for each state.
  • Calculate heat absorbed or released using the latent‑heat formulas.
Materials Needed:
  • Projector or interactive whiteboard
  • Slide deck on changes of state
  • Ice, water, and a hot plate/kettle for demonstration
  • Thermometer
  • Worksheet with diagrams and questions
  • Calculator (for formula practice)
 Introduction:
Begin with a quick poll: “What everyday things involve melting or boiling?” Connect these examples to prior knowledge of particles in solids, liquids and gases. State that by the end of the lesson students will be able to describe each change of state, explain the energy involved, and apply the concepts to exam questions.
Lesson Structure:
  1. Do‑now (5’) – Students list everyday examples of melting, freezing, boiling, evaporation and condensation; share responses.
  2. Mini‑lecture with slides (10’) – Define each change, show particle‑motion diagrams, and discuss endothermic vs. exothermic energy flow.
  3. Demonstration (15’) – Melt ice, boil water, observe evaporation; use thermometer to note temperatures and discuss observations.
  4. Guided worksheet activity (10’) – Label energy flow for each change and match temperatures to the correct process.
  5. Formula practice (10’) – Solve a simple problem using q = m L and q = m c ΔT.
  6. Quick check (5’) – Exit ticket: write one key difference between boiling and evaporation.
Conclusion:
Recap the five changes of state, emphasizing the direction of heat flow and the particle‑level explanations. Collect the exit tickets to gauge understanding, and assign homework: complete a worksheet that includes drawing particle diagrams and a short calculation using latent heat.