“The ice disappeared.”
If that’s a student’s first explanation, point to the shallow container and ask, “What is still in there?”
Look together before offering an explanation. There may be liquid where the solid ice was. A pair of drawings gives you something concrete to return to: what was there at the start, and what can you see now?
Set out one ice cube
Place a plain ice cube in an initially dry, shallow, clear plastic container at room temperature. Divide a page into two drawing spaces labelled Start and Later.
Introduce the ice as solid water and ask students to look for any liquid water already visible. Include it in the first drawing. Explain that an observation records what they actually notice, even if it’s different from what they expected.
Keep the ice in the container to avoid prolonged skin contact, wipe up spills and remind students that the investigation water isn’t for drinking. Leave it at room temperature; don’t add direct heat or boiling water.
Draw what is there
Model a quick outline of the ice and any visible liquid. Add labels such as ice and liquid water; there’s no need for decorative detail.
Return to the container later in the lesson. Ask, “What has changed?” and “What is still there?” Students can draw the new view and explain it aloud, with you scribing labels where useful.
Complete melting isn’t guaranteed during one lesson. Ice size and surrounding conditions affect how long it takes; see Primary Connections’ Year 4 background, Keep it cool. If ice remains, record both the solid ice and the liquid water.
Use the drawing to explain
Suppose the later drawing shows a smaller piece of ice with liquid around it. You could model: “Some ice is still there, and there is liquid water around it. Some of the ice has melted.” Then ask, “Which part of your drawing supports that?”
If no solid ice is visible and liquid remains, try: “I can see liquid water where the ice was. The ice has changed into liquid water.” Ask the same question: “Which part of your drawing supports that?”
Ice is solid water, and melting changes it into liquid water. It hasn’t become a different substance. Treat “disappeared” as an opening for discussion: ask what the student means and which part of the container they’re describing.
Explain what made the ice melt
Students can observe the ice changing shape and liquid collecting. The explanation adds something they can’t see: heat energy moving.
For this water example, solid ice holds its own shape. Liquid water flows and takes the shape of the part of the container it occupies. Heat energy transfers from the warmer surroundings into the colder ice, allowing it to melt. “Warmer” means warmer than the ice; the room doesn’t have to feel hot.
Melting changes solid ice into liquid water; evaporation changes liquid water at its surface into water vapour.
Keep the water for another look
If freezer access is practical, an adult can put the retained water in the freezer for another observation later. Removing sufficient heat from liquid water can turn it back into solid ice. Ask students what they’d look for to describe that change.
For planning, this activity addresses part of Australian Curriculum v9.0 Year 3 AC9S3U04, with partial recording and communication connections to AC9S3I03 and AC9S3I06. See QCAA’s Year 3 Science alignment. It’s an observation task, not a controlled comparison of melting speeds or coverage of the whole achievement standard.
Return to the drawings
Ask students to complete: “At the start I observed ___. Later I observed ___. I think ___ because my drawing shows ___.”
Next time a student says “disappeared”, invite them to point to what remains and explain its state. Use their response to decide what to explore together next.