Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Chemistry
Lesson Topic: State the appearance of the halogens at r.t.p. as: (a) chlorine, a pale yellow-green gas (b) bromine, a red-brown liquid (c) iodine, a grey-black solid
Learning Objective/s:
  • Describe the physical state and colour of chlorine, bromine and iodine at r.t.p.
  • Explain the trend in state and colour down Group VII in terms of atomic radius and intermolecular forces.
  • Write the chemical symbol and state abbreviation (g, l, s) for each halogen and recall iodine’s sublimation behaviour.
Materials Needed:
  • Projector or interactive whiteboard
  • Periodic‑table poster or digital display
  • Handout with halogen table (F, Cl, Br, I, At)
  • Video or images showing chlorine gas, liquid bromine, solid iodine sublimation
  • Worksheet with practice questions
  • Markers and whiteboard
 Introduction:
Begin with a quick “What colour do you associate with chlorine, bromine or iodine?” to activate prior knowledge. Review the halogen group’s position in the periodic table and remind students they will need to state both colour and state at r.t.p. Explain that by the end of the lesson they will be able to list these details accurately and justify the observed trends.
Lesson Structure:
  1. Do‑now (5') – Students write the three halogens and any known colours; share responses.
  2. Mini‑lecture (10') – Present the halogen table, highlight state and colour, introduce the trend explanation.
  3. Guided practice (12') – In pairs, students complete a worksheet filling symbols, state abbreviations and colour descriptions; teacher circulates for support.
  4. Demonstration/video (8') – Show a short video of iodine sublimating and discuss why bromine is liquid.
  5. Check for understanding (5') – Quick quiz (exit ticket) with three statements to mark true/false.
  6. Recap & homework (5') – Summarise key points, assign a worksheet to reinforce symbol‑state‑colour recall.
Conclusion:
Review the three halogens, confirming their colour and state at r.t.p., and ask a few students to explain the trend in their own words. Collect the exit tickets as a retrieval check and remind learners to complete the homework worksheet for additional practice.