FREE PRIMARY SCIENCE · Years 5–6
Change detectives
How can we tell whether a change can be undone?
Students revisit the particle model, investigate melting and dissolving, recover dissolved salt, then look for evidence of new substances in irreversible changes. The final lesson asks students to classify the unit’s changes again and explain their decisions with evidence.
6 free lessons · Australian Curriculum v9
Lessons in this topic
Each lesson includes a teacher plan and activities. Check its materials label before teaching.
The particle puzzle
Why does the outside of a cold drink can get wet on a warm day?
Open free interactive lesson →Melt it, make it again
Chocolate melts in your pocket. Is melted chocolate still chocolate?
Open free interactive lesson →Where did the sugar go?
Stir sugar into water and it seems to vanish. Has it gone?
Open free interactive lesson →Get it back
Sand and salt got mixed into a bucket of water. Can we get both back?
Open free interactive lesson →Something new
Why can’t toast be turned back into bread?
Open free interactive lesson →Change detectives challenge
Four changes from this unit are back on the bench. Which can be undone, and how do you know?
Open free interactive lesson →
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