All lessons › Air: the invisible stuff › Lesson 3
Australian primary science · Year 5 · Lesson 3 of 3
Pump it up
Inquiry question: Does pumping air into a ball make it heavier?
Marked no materials needed
Pattern seeking
What students learn
Air has mass because it is made of particles. Pumping more air particles into a ball increases its mass a little, and more particles hitting the inside of the ball make it harder.
Success criteria
- I can make a reasoned prediction about the ball’s mass.
- I can describe the pattern in the data.
- I can explain the pattern with a particle model and comment on how precise the measurements were.
Preparation and materials
Before this lesson: Students know that air is made of particles that take up space and move fast (lessons 1 and 2).
- One screen or projector to show this lesson’s student view (the ball pumping data) (or print one student view per pair) — 1
- Workbooks or scrap paper, and pencils — 26
Teacher setup
- Open this lesson’s student view (the ball pumping data) on your screen, or print the student view if the internet is unreliable.
- No other preparation is needed.
Safety and adaptations
Follow school science and equipment risk assessment procedures for the materials used.
Review your school policies and curriculum requirements before teaching.
How to investigate
The lesson sequence should leave pupils with evidence to interpret, not only an activity to finish.
- Pairs write a prediction with a reason: will the ball get heavier, lighter or stay the same?
- Read the data table in the student view and describe the pattern for mass and for squash depth.
- Work out about how much mass each 5 pumps added.
- Draw particle diagrams of the flat ball and the full ball.
- Evaluate: why might a bathroom scale (to the nearest 100 g) show no change? What would make the results more trustworthy?
Teacher modelling prompt
Point to the first rows. Think aloud: “0 pumps: 598 grams. 10 pumps: 600 grams. So 10 pumps added 2 grams. That’s about 0.2 grams per pump. Small, but it goes up every time, so there is a pattern.” Model writing a pattern sentence.
Record and explain evidence
Recording question: Does pumping air into a ball make it heavier?
| Pumps | Mass (g) | Change since last row (g) | Squash depth (cm) | What the particles are doing |
|---|---|---|---|---|
| ________________ | ________________ | ________________ | ________________ | ________________ |
Example recording headings; record actual observations, including inconclusive results.
Discussion prompt
How could we be more confident?
Provided example or reference data
Example data: a basketball weighed on a kitchen scale (to the nearest gram) as it is pumped up, and how far it squashes when pressed with a hand (made up for this lesson, but realistic)
| Number of pumps | Mass of ball (g) | How far it squashes when pressed (cm) |
|---|---|---|
| 0 (flat) | 598 | 6 |
| 5 | 599 | 4 |
| 10 | 600 | 3 |
| 15 | 601 | 2 |
| 20 | 602 | 1.5 |
| 25 (full) | 603 | 1 |
Check the data source in the teacher lesson. Illustrative or fictional data are not measurements collected by your class.
Check understanding
What should pupils know? Why does a ball get heavier when you pump air into it?
Explain with evidence: Why does a fully pumped ball squash less than a flat one? Use particles.
Apply the idea: A student weighs a flat and a full ball on a bathroom scale and says there is no difference. Explain why. Stretch (older students): predict and explain what would happen to the ball on a very cold morning.
Teacher answer guidance and saved classroom work are available through the main lesson experience where supported.