Lesson Plan

• Describe a photon as the quantum of electromagnetic radiation.
• Calculate the energy of a photon using E = hν = hc/λ.
• Calculate the momentum of a photon using p = E/c = h/λ.
• Explain how the photoelectric effect, Compton scattering and radiation pressure demonstrate the particulate nature of light.

• Projector and screen
• Whiteboard and markers
• Handout with sample photon calculations
• Computer‑based simulation of the photoelectric effect
• Laser pointer (demonstration of radiation pressure)
• Clickers or paper for quick checks

Begin with a striking question: “Can light push a sail in space?” Connect this to students’ prior knowledge of waves and the relationship c = λν. State that by the end of the lesson they will be able to treat light as particles, calculate photon energy and momentum, and link these ideas to real experiments.

1. Do‑now (5′): short quiz on wave‑based formulas and misconceptions about light.
2. Mini‑lecture (10′): introduce the photon, present Planck’s relation and momentum formula, emphasise mass‑less nature.
3. Guided derivation (8′): derive p = E/c from the relativistic energy‑momentum relation with m₀ = 0.
4. Interactive simulation (10′): students explore the photoelectric effect, answer embedded questions using clickers.
5. Group calculation activity (8′): using the provided table, compute energy and momentum for different wavelengths and discuss trends.
6. Check for understanding (4′): exit‑ticket question – “Give one experimental phenomenon that proves photons carry momentum and explain why.”

Summarise that light’s particulate description allows us to quantify energy and momentum, explaining key phenomena such as the photoelectric effect and radiation pressure. Collect the exit tickets and assign a worksheet of additional photon calculations and a brief reflection on how the dual nature of light influences modern technology.