Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Chemistry
Lesson Topic: State that the mole, mol, is the unit of amount of substance and that one mole contains $6.02 \times 10^{23}$ particles, e.g. atoms, ions, molecules; this number is the Avogadro constant
Learning Objective/s:
  • Describe the mole as the SI unit for amount of substance.
  • State the value of the Avogadro constant ($6.02 \times 10^{23}$ particles per mole).
  • Convert between mass, moles, and number of particles using the appropriate equations.
  • Apply the mole concept to calculate the number of particles in a given mass of a substance.
  • Identify and correct common misconceptions about the mole and Avogadro constant.
Materials Needed:
  • Projector and screen
  • Whiteboard and markers
  • Printed worksheet with conversion problems
  • Scientific calculators
  • Periodic table handout
  • Mole visual model (e.g., beads or spheres)
  • Sample of water for a brief demonstration
 Introduction:
Begin with a quick visual of a pile of beads to illustrate how a seemingly impossible number can be counted. Ask students to recall how atomic mass units relate to grams, linking prior knowledge of mass‑to‑particle ideas. Explain that by the end of the lesson they will be able to define the mole, state Avogadro’s number, and perform basic mole‑based conversions. Success will be demonstrated through a short exit ticket and worksheet completion.
Lesson Structure:
  1. Do‑now (5') – Quick mental task: “If you have 12 eggs, how many dozens?” to activate the idea of counting units.
  2. Mini‑lecture (10') – Define the mole, introduce Avogadro’s constant, and show the visual diagram of $6.02 \times 10^{23}$ particles.
  3. Guided practice (12') – Work through the water example on the board, converting mass → moles → particles.
  4. Pair activity (10') – Students complete worksheet problems converting masses of various compounds to moles and particles.
  5. Concept check (5') – Exit ticket: write the definition of a mole and the numerical value of $N_A$.
  6. Summary discussion (3') – Address the two common misconceptions listed in the notes.
Conclusion:
Recap the definition of the mole and the significance of Avogadro’s constant, highlighting how the conversions link the macroscopic and microscopic worlds. Collect the exit tickets to gauge understanding, and assign a short homework set of additional conversion problems for reinforcement. Encourage students to visualise a mole in everyday terms as a way to remember the magnitude of $6.02 \times 10^{23}$.