Lesson Plan

• Describe the quark composition of protons and neutrons.
• Explain how the weak interaction changes quark flavour in β– and β+ decay.
• Identify the emitted leptons and demonstrate charge and lepton‑number conservation for each decay.
• Apply the quark‑level reactions to predict the final nucleon after a decay.

• Projector or interactive whiteboard
• Slide deck with quark‑level diagrams
• Handout containing decay tables and quark change summary
• Whiteboard and markers
• Clicker/polling system for quick checks
• Worksheet for paired practice problems

Begin with a quick think‑pair‑share asking students how a neutron differs from a proton. Review that nucleons consist of up and down quarks and that the weak force can change quark flavour. State that by the end of the lesson they will be able to trace the quark changes in β– and β+ decay and name the accompanying leptons.

1. Do‑now (5') – short quiz on quark content of protons and neutrons.
2. Mini‑lecture (10') – introduce the weak interaction and W± boson exchange with slides.
3. Guided example (10') – work through β– decay, writing the quark transition and lepton emission on the board.
4. Paired activity (12') – students complete a worksheet mapping β+ decay, drawing the quark change and checking charge conservation.
5. Interactive poll (5') – concept‑check via clickers on key points.
6. Summary discussion (8') – consolidate differences between β– and β+ decay using the summary table.
7. Exit ticket (5') – each student writes one sentence describing the quark change for each decay type.

Recap that β– decay converts a down quark to an up quark while β+ decay does the opposite, each accompanied by the appropriate lepton pair. Collect exit tickets to gauge understanding, and assign a homework set where students balance decay equations and label the quark changes.