How is Heat Transferred by Conduction?
When you touch objects in your kitchen, such as a chair, the countertop, or a potholder, some feel cooler than others. If heat is transferred from the warmer object to the cooler one until equilibrium is reached, you'd expect all of the objects in your kitchen to be the same temperature - room temperature - and they are. So what's going on?
What is happening between your hand (that's about 33°C) and the countertop that you touch (that's about 20°C)?
This is the case of heat transfer by conduction. Energy from the particles in your 33°C hand is transferred to the particles in the cooler 20°C countertop. This mode of energy transfer - the transfer of energy from one particle to another or from one material to another when the two are in direct contact - depends upon the ability of a material to transmit heat by conduction.
This Week's Plan
In this session, you'll investigate heat transfer by conduction. In a video of heating blue water, you'll sort out heat transfer by conduction from heat transfer by convection. In a hands-on investigation, you'll investigate the ability of different materials to conduct heat. You'll use Molecular Workbench to investigate conduction from a molecular perspective.
Although we’re focusing on conduction in this session, conduction is often acting together with other modes of heat transfer. When you resume your science investigations in Session 8, you'll be considering heat transfer by radiation as well as conduction and convection.
- Understand how heat is transferred by conduction.
- Understand that conductivity is a characteristic property of materials.
What you need
- 3 identical ice cubes
- a metal surface, such as a cake pan
- a wood surface, such as a bread board or 2x4
- a stone surface, such as an unglazed ceramic tile, a flat stone, or a marble counter
From your kit
- Aluminum thermometers