This lesson introduces students to the fundamental process of diffusion, helping them understand how particles move and why this movement is essential for life. Learners explore the factors that affect the speed of diffusion, building secure scientific reasoning that links particle behaviour to real biological needs. The session emphasises why diffusion is vital for cell survival, including gas exchange and nutrient uptake.

The lesson includes peer/group learning, mini tasks, and a print‑ready worksheet with an adaptive version to support all learners.

Students will be able to:

• Describe diffusion and how it works
• Identify factors that change the speed of movement
• Explain why diffusion is essential for cells to stay alive

**Some visuals in this resource were made with AI to help bring ideas to life and support student understanding.