Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Chemistry
Lesson Topic: Use a Roman numeral to indicate the oxidation number of an element in a compound
Learning Objective/s:
  • Identify oxidation numbers of elements in compounds using standard rules.
  • Convert oxidation numbers to Roman numerals and correctly write chemical formulas.
  • Explain the role of oxidation numbers in redox reactions.
  • Apply the notation to transition‑metal compounds and balance simple redox equations.
Materials Needed:
  • Projector or interactive whiteboard
  • Chemistry textbook or IGCSE syllabus handout
  • Worksheet with oxidation‑number exercises
  • Periodic‑table posters highlighting transition metals
  • Sample chemical‑formula cards
  • Answer key for practice questions
 Introduction:
Begin with a quick visual of colourful transition‑metal salts to spark curiosity about why they have different names. Review the concept of oxidation numbers and how they indicate electron loss or gain. State that today students will learn to express these numbers with Roman numerals and use the notation in chemical formulas.
Lesson Structure:
  1. Do‑now (5’) – Students write oxidation numbers for given simple compounds on a sticky note.
  2. Mini‑lecture (10’) – Explain rules for assigning oxidation numbers and introduce Roman‑numeral notation with examples.
  3. Guided practice (12’) – Whole‑class work through examples (Fe(III)Cl₃, Cu(II)SO₄, Mn(IV)O₂) on the board.
  4. Pair activity (15’) – Worksheet where pairs determine oxidation numbers and rewrite formulas using Roman numerals for a set of transition‑metal compounds.
  5. Redox connection (8’) – Brief demonstration of a redox reaction, highlighting how oxidation numbers change and how the notation aids balancing.
  6. Check for understanding (5’) – Exit ticket: write the Roman‑numeral oxidation state for Cr in Cr₂O₇²⁻.
Conclusion:
Summarise that Roman numerals provide a clear way to show oxidation states, especially for transition metals. Students complete an exit ticket confirming they can convert oxidation numbers to Roman numerals. Assign homework: finish the additional worksheet on balancing redox equations using the new notation.