In this lesson students explore heat in familiar contexts and define heat as a type of energy. They are introduced to the concept of heat transfer and explore how to measure temperature.
Pierre near the oven
Introduce students to the context of the unit by introducing apprentice chef Pierre and then reading/showing them Letter 1 from apprentice chef Pierre.
Explain that Pierre is an apprentice chef, so he is still learning and needs the class to help remind him about the concepts of heat.
Inform students they will be studying heat and sending letters to Pierre following each lesson telling him what they have learnt so that he might better understand his cooking and be able to cook for a banquet.
- Ask students to make suggestions about what heat is and discuss their responses. Inform students that heat is a type of energy and that energy is the ability to make things happen. Explain that heat energy is not always easy to see, but one way to observe it is to use our sense of touch.
- Have students:
- move around the room and touch items around them
- describe whether they think the item is hot or cold
- record their observations in their science journals
- share their observations with the class.
- Conduct the teacher demonstration. The procedure for this demonstration is in Background information.
- Show students a thermometer and ask them to make suggestions about its purpose and how it functions. Explain that heat is transferred from a system (or an object) of higher temperature to an object of lower temperature. Inform students that thermometers are used to measure the temperature of something and that temperature is referred to as being either hot or cold.
- Demonstrate how to use a thermometer using the water samples from the teacher demonstration.
- Conduct the student activity – thermometer practice.
- Put students into pairs or small groups so they can compare temperature results.
- Distribute to each group, a plastic cup containing warm water (approx. 37 °C) and a plastic cup containing cold water (approx. 3 °C).
- Students take the temperature of each cup of water every 10 minutes for half an hour and record their results. (Students take turns using the thermometer and compare their results to ensure each person is measuring correctly.)
- Ask students to make a prediction about what they think will happen to the temperature of each cup of water over the half-hour.
- Students share their results with the class.
- Ask students to use their knowledge from the lesson to help explain why the temperature of each cup of water changed.
Remind students that heat moves from one system (object or place) to another because of differences in the temperatures of the systems. Explain that, if you had two systems with equal temperatures, there would be no obvious flow of heat energy. When you have two systems with different temperatures, the heat energy flows.
Ask students to write a letter to apprentice chef Pierre explaining the concepts they have learnt during the lesson.
Inform students that there are different types of heat transfer and they will be exploring two types – convection and conduction.
Discuss the safety implications of working with heat prior to the next lesson.