Science
Science vocabulary: particles and diffusion
Use a five-term glossary and a supplied particle pattern to explain concentration and net diffusion. The pupil task compares 12 and four illustrative particles in equal volumes across an open boundary. A separate companion gives matches and a model explanation, with HTML alternatives for both files.
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Use a five-term glossary and a supplied particle pattern to explain concentration and net diffusion. The pupil task compares 12 and four illustrative particles in equal volumes across an open boundary. A separate companion gives matches and a model explanation, with HTML alternatives for both files.
Pupil worksheet. Use the preview for diagrams and layout.
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Pupil activity Science vocabulary: particles and diffusion Five terms Particle: a small unit in a model of matter. Concentration: number of particles in a stated volume. Diffusion: net movement from higher to lower concentration due to random particle motion. Net movement: the overall direction after considering movements in both directions. Membrane: a boundary whose properties determine what can pass in a stated context. Match all five A. overall direction after movements in both directions; B. a boundary with particular passage properties; C. number per stated volume; D. a small model unit; E. net spreading from higher to lower concentration. Terms: particle, concentration, diffusion, net movement, membrane. Supplied particle pattern Left region, volume 1 cm³: ● ● ● ● / ● ● ● ● / ● ● ● ● (12 particles). Right region, volume 1 cm³: ● ● / ● ● (4 particles). Both regions have equal volume. The dots are an illustrative count, not an actual measurement. The boundary is open to these particles for this diffusion example. Explain the pattern 1. State which side has higher concentration, with the counts and equal volumes. 2. Explain the direction of net diffusion across this open boundary. 3. Explain why “all particles move only one way” is inaccurate. 4. If the boundary were a membrane, name a property you would need before predicting passage. Working space Higher concentration and evidence: ______. Net movement: ______. Random motion explanation: ______. Missing membrane information: ______. Check Particles continue moving randomly even when concentrations become equal. Equal concentration gives no overall net movement. The example does not establish the permeability of a different membrane. Pupil activity | Page 1 of 1
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Teacher companion Science vocabulary: particles and diffusion Matching key A net movement; B membrane; C concentration; D particle; E diffusion. Pattern model The left region has 12 particles per cm³ and the right 4 per cm³. The overall net movement is left to right down the concentration gradient, while individual particles move randomly in both directions. At equal concentration, motion continues with no net movement. Membrane limit For a membrane boundary, a prediction requires its permeability to the specific particles. Do not assume that all substances cross all membranes. Teacher companion | Page 1 of 1
A teaching sequence
Pupils should use counts and volumes to identify the higher concentration and explain net movement from left to right. They should distinguish overall net movement from individual random motion and identify permeability information needed for a different membrane.
Match the five terms precisely
Check particle, concentration, diffusion, net movement and membrane against the glossary. Ask why a particle count needs a stated volume to support a concentration comparison.
Why does a particle count need a stated volume for concentration?
Compare counts in equal volumes
Record 12 particles per cm³ on the left and four per cm³ on the right. Use those values to explain which region has higher concentration rather than relying only on how crowded the dots look.
Which region has the higher particles-per-cubic-centimetre value?
Explain net movement across the open boundary
Describe net diffusion across the open boundary while recognising motion in both directions. Ask whether “all particles move only one way” fits the definition of net movement.
Why does net movement not mean every particle moves only one way?
Distinguish equilibrium from membrane uncertainty
Discuss what happens at equal concentration and complete the missing-membrane-information field. Separate the given open boundary from an unprovided membrane with unknown passage properties.
What passage property would you need for a different membrane?
Before you teach
Look for the thinking behind an answer, choose the support your class needs and leave room for an independent response.
What to look for
A useful answer gives net movement left to right while particles move randomly in both directions. At equal concentration, motion continues with no overall net movement. If a pupil predicts that every particle crosses any membrane, ask which permeability property for these particles must be known before that prediction.
Give a little support
Place the two counts beside the equal-volume labels and use the stem “There are… particles per cm³, so…”. Draw arrows both ways, then add a separate arrow for the overall net direction. Discuss the difference before writing a complete diffusion explanation.
Take the idea further
Reconsider the same pattern with a membrane boundary of unspecified permeability. Write the question that must be answered before predicting passage, then compare this uncertainty with the supplied open-boundary case. Explain why a concentration difference alone does not establish that these particles can cross.
Things to keep in mind
Dots are illustrative counts. A different membrane requires its specific permeability; not every particle crosses every membrane.
Keep the idea. Make it yours.
Bring your topic, learning goal and class context to PLAI™, then review what you create.
Ideas to try with your class
Sample teaching perspectives on what to try, what to adapt and what to watch for.
Meet The Creators
Meet a creator whose teaching interests connect with this template.
Open Book Pause
The one-page particle activity defines five terms, then asks pupils to compare particle counts in stated volumes and explain net movement from higher to lower concentration. It specifically distinguishes the overall direction from individual random motion.
Clear Example
The vocabulary sequence prepares pupils to interpret the diagram and state the direction of net movement. The final membrane prompt asks what additional permeability information would be needed in another case rather than assuming every boundary behaves alike.
Glue Stick Club
Count particles in equal volumes first, name which side has the higher concentration, then describe random movement in both directions and the net result. Keep volume units visible during the comparison.
Reread Reminder
The diagram models a simplified case and does not establish what can cross an unspecified membrane. Use the stated counts and volumes, and require new evidence before applying the explanation to a different membrane.