Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Chemistry
Lesson Topic: Atoms, molecules and stoichiometry: relative masses of atoms and molecules, the mole, Avogadro constant, empirical and molecular formulae, chemical equations and calculations
Learning Objective/s:
  • Describe relative atomic and molecular masses and calculate them for given formulas.
  • Explain the mole concept and use Avogadro’s constant to convert between mass, moles, and number of particles.
  • Determine empirical and molecular formulas from percent‑composition or mass data.
  • Write, balance, and interpret chemical equations.
  • Perform stoichiometric calculations (mass‑mass, mole‑particle, volume‑mole) using balanced equations.
Materials Needed:
  • Projector or interactive whiteboard
  • Chemistry textbook or printed notes on stoichiometry
  • Worksheet with practice problems
  • Periodic‑table handouts
  • Scientific calculators
  • Molecular model kits (optional)
 Introduction:
Begin with a quick think‑pair‑share: “If you had 1 mol of carbon atoms, how many particles would that be?” This activates prior knowledge of the mole concept. Review the link between relative masses and molar mass, then outline today’s success criteria: students will calculate relative masses, derive empirical/molecular formulas, balance equations, and solve stoichiometric problems.
Lesson Structure:
  1. Do‑now (5') – Calculate the relative molecular mass of glucose on a mini‑whiteboard.
  2. Mini‑lecture (15') – Explain relative masses, the mole, and Avogadro’s constant with short examples.
  3. Guided practice (20') – Work through the 40 % C/H/O empirical‑formula example; teacher circulates.
  4. Demonstration (10') – Live balancing of propane combustion on the projector; students verify each step.
  5. Collaborative problem solving (20') – Groups complete worksheet sections on mass‑mass, mole‑particle, and volume‑mole calculations.
  6. Quick check (5') – Exit ticket: one stoichiometry question answered on a sticky note.
Conclusion:
Summarise how the mole bridges the atomic and macroscopic worlds and how balanced equations enable quantitative predictions. Collect exit tickets, review common errors, and assign homework: a set of mixed stoichiometry problems to reinforce today’s skills.