Heat Changes Matter

Overview

Building on Lesson 7, students investigate how adding or removing heat energy changes matter. Through teacher demonstrations and a collaborative investigation using ice and warm water, students observe melting, evaporation and condensation, record evidence in drawings and a simple data display, and explain their observations using scientific vocabulary.

Learning intentions

Students will:

• investigate how heating and cooling change the state of matter
• make predictions and observe changes during a fair investigation
• record observations using labelled scientific diagrams and categorical data
• identify patterns in observations and explain changes using evidence
• communicate clearly using scientific vocabulary

Success criteria

I can:

• identify how heating and cooling change solids, liquids and gases
• make a prediction before an investigation
• draw and label what I observe
• identify patterns in our class data
• explain melting, evaporation and condensation using evidence

Curriculum links

• Science: Uses information to investigate the effects of energy on physical systems.
• Science: Poses questions and plans fair tests about the effects of energy on physical systems.
• Science: Uses and interprets data to describe patterns and relationships.
• English and Mathematics: Communicates in collaborative situations, writes scientific observations, collects and interprets categorical data, and uses measurement to compare observable changes.

Lesson structure (60 minutes)

1. 0–8 min · Engage and connect. Display the question “How does heat energy change matter?” using the opening question and Lesson 7 review slide. Show an ice cube and ask students what may happen in a warm classroom and why. Students turn and talk, then share prior learning about solids, liquids and gases. Record predictions using the words heat, cool, solid, liquid and gas.

2. 8–18 min · Teacher demonstration. Use the states-of-matter visual and change-of-state slides to explain that heating can cause melting and evaporation, while cooling can cause condensation and freezing. Place an ice cube in a clear dish and hold a cool metal lid or mirror above a cup of warm water, without students touching the equipment. Students observe carefully and complete the prediction section of the heat energy investigation sheet. Ask: “What evidence shows that the ice is melting?” and “Where did the water droplets on the lid come from?”

3. 18–35 min · Collaborative investigation. Organise groups of four with roles: equipment manager, observer, recorder and reporter. Provide each group with an ice cube in a clear container and a small cup of warm water; adults pour the warm water and students do not handle hot equipment. Students predict, observe at five-minute intervals and draw labelled diagrams showing the ice changing from solid to liquid. They may observe water vapour above the warm water and droplets forming on a cool surface. Students record changes and simple measurements, such as the number of minutes until melting begins, on the heat energy investigation sheet. Circulate and ask, “What changed?”, “What stayed the same?” and “What evidence supports your explanation?”

4. 35–48 min · Drawing and organising data. Prepare a class chart with the categories solid, liquid, gas or water vapour and droplets from condensation. Students contribute one labelled drawing or observation to the category that best represents the change they observed. Guide students to construct the display with one drawing representing one observation. Use the class data-display instruction and discussion slides to prompt: “Which category has the most observations?”, “Which has the fewest?”, and “What does our display tell us about heat energy?” Students compare the effectiveness of drawings and the chart for organising information.

5. 48–55 min · Evidence-based explanation. Model a sentence such as: “The ice melted because it gained heat energy and changed from a solid to a liquid.” Students write or orally rehearse one explanation about melting, evaporation or condensation using the frame: “I observed ____. This shows that heat energy ____, because ____.” Invite several students to share and identify the evidence in each explanation. Return to the scientific vocabulary and explanation slide.

6. 55–60 min · Plenary and assessment. Students complete the exit questions on the final reflection and exit ticket: “What happens when ice gains heat?”, “What happens when water vapour cools?”, and “Draw and label one change of state.” Students share one new idea with a partner before handing in their sheets.

Resources

• the heat energy and states-of-matter slide deck
• the heat energy investigation sheet
• Ice cubes
• Clear plastic cups or dishes
• Warm water, prepared and poured by the teacher
• Cool metal lids, trays or mirrors for condensation
• Chart paper or whiteboard
• Markers, pencils and blank drawing paper
• Timer or classroom clock
• Paper towels and a spill tray

Assessment

• Observe whether students make a prediction, use the investigation safely, identify changes and contribute relevant evidence.
• Check labelled diagrams, recorded observations and the class categorical data display for accurate sorting and recognition of patterns.
• Use the exit ticket to assess whether students can explain that heating and cooling cause physical changes, including melting, evaporation and condensation.

Differentiation

• Provide picture prompts, word banks and sentence starters using heat, cool, solid, liquid, gas, melt, evaporate and condense. Allow students to explain orally before writing.
• Pair students strategically and assign clear roles. Provide pre-drawn state labels and partially completed diagrams for students requiring additional support.
• Extend confident students by asking them to compare two observations, explain why the rate of melting may differ, or suggest how to make the investigation a fairer test.
• Support EAL/D and students requiring adjustments with gestures, real objects, repeated modelling, enlarged visuals and opportunities to record through labelled drawing, speech or scribing.