Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Chemistry
Lesson Topic: Determine the electronic configuration of elements and their ions with proton number 1 to 20, e.g. 2,8,3
Learning Objective/s:
  • Describe the Aufbau, Pauli exclusion, and Hund rules for electron placement.
  • Write the ground‑state electron configuration for elements Z = 1‑20 using the 2,8,3 notation.
  • Determine the electron configuration of cations and anions by adding or removing electrons from the outermost subshell.
  • Apply the noble‑gas core concept to verify configurations of ions.
Materials Needed:
  • Projector or interactive whiteboard
  • Slide deck with electron‑configuration tables
  • Worksheet with practice ion configurations
  • Periodic‑table handouts
  • Whiteboard markers and erasers
  • Colored tokens or electron‑dot models (optional)
 Introduction:
Begin with a quick recall of the three rules that govern electron arrangement. Ask students to predict the configuration of helium and then of sodium, linking to prior knowledge of shells. Explain that by the end of the lesson they will be able to write configurations for any element or ion up to calcium using the 2,8,3 shorthand.
Lesson Structure:
  1. Do‑now (5'): Short quiz on Aufbau, Pauli and Hund rules on the board.
  2. Direct instruction (10'): Present the subshell order (1s → 2s → 2p → 3s → 3p) and demonstrate configurations for H–Ne.
  3. Guided practice (15'): Work through Na⁺ and O²⁻ examples together using slides and whiteboard.
  4. Independent practice (15'): Students complete worksheet items for Mg²⁺, Al³⁺, Cl⁻, Ca²⁺ while teacher circulates.
  5. Check for understanding (5'): Exit ticket – write the configuration for K⁺ and identify its noble‑gas core.
  6. Summary discussion (5'): Review key steps, address misconceptions, and reinforce the 2,8,3 pattern.
Conclusion:
Summarise how the three rules and the noble‑gas core guide the writing of configurations for neutral atoms and ions. Collect the exit tickets as a formative check and assign a homework sheet to practice configurations for elements 21‑30. Remind students to use the 2,8,3 pattern and to verify the number of valence electrons remaining.