All lessons › Change detectives › Lesson 6
Australian primary science · Years 5–6 · Lesson 6 of 6
Change detectives challenge
Inquiry question: Four changes from this unit are back on the bench. Which can be undone, and how do you know?
Check practical materials
Classifying
What students learn
Changes can be classified as reversible or irreversible using evidence.
Success criteria
- I can classify each mystery change and give evidence.
- I can write a claim, evidence and reasoning.
- I can explain how new evidence changed my thinking.
Preparation and materials
Before this lesson: Evidence for reversible and irreversible changes (lessons 2–5).
- Station A: ice in cups — 4 cups
- Station B: salt, cups of water, spoons — 4 sets
- Station C: bicarb soda, vinegar, cups, safety glasses — 4 sets
- Station D: the rust jars from lesson 5 — 3 jars
- Gloves for handling steel wool — 1 pair at station D
- Individual records (assessment) — 26
Teacher setup
- Set up four stations with instruction cards.
- Print one individual record per student.
Safety and adaptations
- Safety glasses at station C.
- Gloves for steel wool at station D.
- No tasting.
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.
- Visit each station. Record your observations.
- Classify each change as reversible or irreversible.
- Choose one change and write a claim, evidence and reasoning.
- Hear another group’s evidence. Revise your explanation if needed, and say why.
Teacher modelling prompt
Write: Claim: “Melting ice is reversible.” Evidence: “When we froze the water, it became ice again.” Reasoning: “No new substance formed; only the arrangement of particles changed.” Ask: “What would make this explanation stronger?”
Record and explain evidence
Recording question: Which mystery changes are reversible, and what is my evidence?
| Station | What I observed | Reversible or irreversible? | My best evidence |
|---|---|---|---|
| ________________ | ________________ | ________________ | ________________ |
Example recording headings; record actual observations, including inconclusive results.
Discussion prompt
Which claim is supported by evidence from this unit?
Check understanding
What should pupils know? Choose one mystery change. Is it reversible or irreversible? Write a claim, evidence and reasoning.
Explain with evidence: Describe something you changed your mind about in this unit, and the evidence that changed it.
Apply the idea: Is making toast from bread reversible? Is freezing orange juice into ice blocks reversible? Explain each.
Teacher answer guidance and saved classroom work are available through the main lesson experience where supported.