Use visible observations to test explanations about matter too small to see.
What it is about
Use simple particle models to explain observable properties, including gases.
Grade 5 · 10–11 years · 30 challenges
Before you begin
Grade4 energy transfer, structures, waves and Earth processes.
What the class will do
Sort into groups · 6 challenges
Separate records and explanations
Sort directly supplied observations or setup details separately from explanations about unseen particles. Both can be useful; they are different kinds of statement.
Choose and explain · 24 challenges
Test the explanation
Use each complete case to compare particle explanations. Keep actual observations separate from symbolic model details.
Using it in class
Everyone proposes a claim and cites a record before the rotating representative acts. All cases are supplied teaching records, not instructions to conduct experiments. Discuss uncertainty and system boundaries. Full bank: 30–45 minutes.
Give everyone time to think and discuss before one pupil acts at the board. The class explains and confirms together; hints and explanations stay until you move on.
Use an up-to-date browser on a computer connected to a whiteboard or shared display. Touch, mouse and keyboard; optional audio and reduced motion. No pupil accounts or personal devices.
Choose from 5 challenges up to the full activity. Discussion determines the duration: you set the pace.
A look inside the activities
Sort into groups
Record: air is added to a flexible bag, which expands. Sort what was recorded and what the particle model explains.
Air particles enter the bag
The bag becomes wider
The moving gas particles press on its walls
Groups: Recorded observation or setup · Particle-model explanation
Explanation and discussion
Expansion is recorded. Entering, moving gas particles provide a model explanation; the record is not a photograph of individual particles.
How could an unseen cause help explain a visible change?
Choose and explain
A capped bottle contains air but no liquid or visible solid. Which explanation fits a particle model?
It contains no matter because it looks clear
It contains matter only while someone squeezes it
It contains gas matter even though its tiny particles are unseen
Explanation and discussion
Air is gas matter. Its particles are too small to see individually; clear appearance does not make the bottle a space without matter.
What observable effect could provide evidence for the trapped air?