Lesson Plan

• Describe the three main types of radioactive emission (α, β, γ) and their characteristic properties.
• Explain why radioactive decay is spontaneous and random, using the concept of half‑life.
• Write balanced nuclear equations for α, β⁻, β⁺ and γ emissions.
• Identify appropriate shielding materials for each type of radiation.

• Projector or interactive whiteboard
• PowerPoint slides with diagrams of decay processes
• Printed worksheets for equation practice
• Radioactive decay simulation (e.g., PhET)
• Nuclear charts or element cards
• Shielding demonstration items (paper, plastic, lead sheet)

Begin with a striking image of a glowing cloud chamber to capture interest. Ask students what they know about unstable atoms and isotopes from previous lessons. State that by the end of the lesson they will be able to identify decay types, write nuclear equations, and explain why decay is random.

1. Do‑now (5') – quick quiz on atomic structure and isotopes.
2. Mini‑lecture (10') – introduce instability, spontaneous decay and half‑life.
3. Interactive simulation (10') – students observe random decay events and identify emitted particles.
4. Guided practice (12') – write balanced nuclear equations for given decays and discuss particle properties.
5. Shielding activity (8') – groups match each radiation type to the correct shielding material.
6. Check for understanding (5') – exit ticket: one sentence explaining why decay is random.

Recap the key ideas: types of radiation, their properties, and the random nature of decay governed by half‑life. Collect exit tickets to gauge understanding, and assign homework to complete a worksheet on writing balanced nuclear equations and selecting shielding.