Lesson Plan

• Describe mass defect and its relationship to nuclear binding energy.
• Calculate binding energy per nucleon for given nuclides.
• Explain why fusion of light nuclei and fission of heavy nuclei release energy using the binding‑energy curve.
• Apply the Q‑value equation to determine the energy released in sample fusion and fission reactions.
• Interpret a binding‑energy‑per‑nucleon plot to predict energetically favorable nuclear reactions.

• Projector or interactive whiteboard
• Slide deck showing the binding‑energy curve
• Printed worksheet with nuclide table and Q‑value problems
• Calculators or spreadsheet software
• Isotope cards for a sorting activity
• Exit‑ticket slips

Show a striking image of a star and a nuclear power plant and ask students what common factor powers both.

Recall their prior work on mass‑energy equivalence and basic nuclear terminology.

Explain that today they will discover how binding energy per nucleon determines whether a nuclear reaction releases energy.

1. Do‑now (5'): Quick calculation of the mass defect for ^4He using provided masses; teacher checks answers.
2. Mini‑lecture (10'): Introduce mass defect, binding energy, binding‑energy per nucleon, and the characteristic curve; use slides.
3. Guided practice (12'): In pairs, students plot binding‑energy per nucleon for the given nuclides and identify the peak near iron‑56.
4. Application activity (15'): Worksheet problems – calculate Q‑values for D‑T fusion and ^235U fission; teacher circulates for support.
5. Concept check (5'): Think‑pair‑share: students explain why fusion releases energy for light nuclei and fission for heavy nuclei.
6. Exit ticket (3'): Write one sentence summarising the relevance of binding energy per nucleon to nuclear reactions.

Summarise that a nucleus’s position on the binding‑energy curve predicts the direction of energy release.

Students demonstrated this by calculating Q‑values for both a fusion and a fission example.

For homework, assign additional reactions for Q‑value calculation and ask students to sketch the binding‑energy curve.