Touching different materials in the kitchen

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Key Learning Points

1. Temperature
2. Conduction of heat
3. Rate of heat conduction

Students are told to touch a few materials in the kitchen and explain their sensation of coldness in terms of the physics of heat they learned. The activity aims at introducing the basic concepts of heat conduction and clarifying some misconceptions that may arise from our daily experience.

	How do you feel when touching a metal surface?

1. The activity is better performed on a cold day. Students are told to touch a few materials in the kitchen at their home. For example, they may touch the metal of a sink, the glass of a window, and the wood of a table, etc.
2. Ask the students why some materials feel colder than others.
3. The students will form groups and discuss their sensation based on the physics of heat they learned and present their result.
4. The teacher summarizes and comments on the students' results.

1. Your hand feels cold when touching materials like glass and metal. Do you think these materials have lower temperatures than others in the kitchen?
2. Then how do you explain the sensation of coldness? How is it related to heat conduction?
3. Based on your answer to question 2, rank three materials, namely, glass, metal and wood by their ability of heat conduction. Explain your answer.