Lesson Plan

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Lesson Plan
Grade: Year 12 Date: 17/01/2026
Subject: Physics
Lesson Topic: describe a simple model for the nuclear atom to include protons, neutrons and orbital electrons
Learning Objective/s:
  • Describe the basic structure of a nuclear atom, identifying protons, neutrons and orbital electrons.
  • Explain how charge balance determines the number of electrons in a neutral atom.
  • Compare isotopes by varying neutron number while keeping proton number constant.
  • Interpret simple diagrams that show the nucleus and electron shells.
  • Apply the 2n² rule to determine electron capacity of each shell.
Materials Needed:
  • Projector or interactive whiteboard
  • PowerPoint/Google Slides with atom diagram
  • Printed worksheet with isotope table and shell‑filling exercises
  • Model kits (foam balls for protons, neutrons, and electron shells) – optional
  • Markers and chart paper for group sketch
 Introduction:
Begin with a quick image of a fruit with a tiny seed to spark curiosity about how most of an atom’s mass is hidden inside a minuscule nucleus. Review prior knowledge of protons, neutrons and electrons from earlier lessons. Explain that today’s success criteria are to be able to draw a simple nuclear model and justify electron numbers using charge balance.
Lesson Structure:
  1. Do‑now (5’) – short quiz on particle charges and relative masses.
  2. Mini‑lecture (10’) – present the nuclear model, emphasizing size differences and mass distribution.
  3. Interactive diagram activity (12’) – groups build a nucleus (Z protons, N neutrons) and add electron shells using the 2n² rule.
  4. Isotope exploration (8’) – examine the isotope table, calculate mass numbers and discuss stability.
  5. Guided practice (10’) – worksheet problems on charge balance and shell filling for sodium and carbon isotopes.
  6. Check for understanding (5’) – exit ticket: “Write the number of electrons in a neutral atom with Z=15.”
Conclusion:
Summarise that the nucleus holds almost all the atom’s mass while electrons occupy defined shells that balance charge. Collect exit tickets, address any misconceptions, and assign homework to sketch the nuclear model of an element of their choice, labeling protons, neutrons and electrons.