Lesson Plan

• Describe how inter‑particle forces differ in solids, liquids and gases.
• Explain the relationship between particle motion, temperature and pressure.
• Predict how heating or cooling changes the state of a material using the particle model.
• Analyse how force strength influences macroscopic properties such as density and viscosity.

• Projector and screen
• PowerPoint/Google Slides presentation
• Student worksheet with tables and diagrams
• Interactive particle‑model simulation (e.g., PhET)
• Diagram handouts of particle arrangements
• Whiteboard and markers

Begin with a quick demonstration of ice melting to spark curiosity about why solids change shape when heated. Ask students what they already know about the states of matter and how particle motion might relate to temperature. Explain that by the end of the lesson they will be able to use the particle model to explain observable properties and predict state changes.

1. Do‑now (5'): short quiz on states of matter and particle motion.
2. Mini‑lecture with slides (10'): introduce the particle model, inter‑particle forces and typical distances.
3. Guided table activity (10'): students complete a table comparing forces, distances and resulting properties for solids, liquids and gases.
4. Simulation demo (8'): show particle motion at different temperatures and discuss kinetic energy.
5. Group problem‑solving (12'): predict how heating a liquid or cooling a gas changes its density, shape and volume; record answers on worksheet.
6. Check for understanding (5'): exit ticket – one sentence explaining why gases have low density.

Recap the key idea that forces and distances between particles, together with their motion, dictate the macroscopic properties of matter. Collect exit tickets and highlight a strong response as a model answer. Assign homework: complete a worksheet that asks students to predict the effect of heating or cooling on a given material using the particle model.