Video · Teachers Media
Action Teacher Video Chemical Puppets
A memorable science demonstration teachers can bring back into class the day after INSET: chemical reactions staged as a small piece of visible theatre. The point is not the spectacle — it's that a good demo does two things at once, engaging pupils emotionally while giving them something concrete to reason about.
About this video
Chemistry demonstrations sit in a long UK tradition, from Faraday's Royal Institution Christmas Lectures to today's Bunsen burner classics. Their pedagogical power is well established: a well-chosen demo gives every pupil a shared experience to think from, cuts through the abstraction of chemical equations, and creates the kind of moment they remember years later.
The trap is confusing entertainment with learning. A demo that draws gasps but leaves no residue in pupils' understanding is a missed opportunity. Strong demonstrators wrap the moment in structured prompts — a prediction beforehand, an observation during, an explanation afterwards — so the wow moment becomes a peg the concept can hang on.
For KS3 and KS4 chemistry, the highest-leverage demos are usually the ones that make an invisible process visible: colour changes that show a reaction has happened, gas produced that can be tested, energy released that can be felt. Pair the demo with the underlying particle-model reasoning and pupils have something to write about, not just something to remember.
A structure for demonstration lessons
- Predict. Show the setup silently. Ask pupils to write or share what they think will happen — and why. Their prior reasoning matters more than being right.
- Perform. Run the demo. Slow down at the pivot moment. Ask pupils to note what they actually see, not what they thought they would.
- Explain. Work through the underlying chemistry — particle model, equation, energy change. This is where the demo pays for itself.
- Apply. Give a linked problem or a similar reaction to reason about. Can they now predict something they haven't seen?
Discussion prompts
- Which of your favourite demonstrations are genuinely helping pupils reason, versus mostly performing for engagement?
- When you run a demo, how much of pupils' cognitive load is on making sense of what happened, versus watching what happens?
- How could you build in a written or spoken prediction step so pupils commit to a hypothesis before they see the outcome?
Try this in your classroom
- Take a demo you already do and add a "predict → observe → explain" structure. Notice how much richer the discussion becomes.
- After a demo, ask pupils to draw the particle-level explanation. Their diagrams tell you exactly where the concept has and hasn't landed.
- Film one of your demos on a phone. Watch it back with a colleague and ask: what would a pupil sitting near the back have actually seen?