Cambridge Secondary (7-9). Stage 8. Science. Learner's Book - Unit 3: Forces and energy - Question 125

Part 2: Pressure and temperature in gases. In this activity, you will observe the effect of changing temperature on the pressure in a gas. Work in groups of two or three. You will need: empty plastic bottle (0.5–2 litre) with lid; access to a warm place; access to a cold place, such as a refrigerator. Method: 1 Take the lid off the bottle. 2 Leave the bottle and the lid in a warm place for 5–10 minutes. 3 Put the lid tightly on the bottle without squeezing the bottle. Do this while the bottle is still in the warm place. 4 Put the bottle into a cold place for 15–20 minutes. 5 Observe what has happened to the bottle.

Predict what would happen if you did this activity the other way around. The open bottle starts in the cold place, then the closed bottle is taken to a warm place. Include ideas about particles and pressure and include the observation that you would make.