Resources: Sticky tape, drawing pins, petroleum jelly, tin can, kettle, stopwatch, metal samples cut into strips of the same thickness and length e.g. aluminium, copper, zinc, tin, iron.
Handout: An investigation sheet for the students to complete.
Look at the picture of the saucepan. Why are the pan and the handle made from different materials? The students should discuss their ideas with their talk partners.
Work through the presentation, discussing the different factors that affect how heat travels. Once complete, there are some worksheet questions to complete on metal conductivity. This is followed by the mission assignment video that introduces the practical on heat transfer in metals. The practical also has a worksheet for the students to use.
Career Film: Iwan Saunders Jones works as a Systems Engineer for Magnox.
Expert Film: This is Yasmin Jones, who works as a Health Physics Monitor for Magnox. Yasmin talks about how heat is transferred through solids.
Students will be comparing the thermal conductivity of metals.
Support: There are support questions on the worksheet that the students can complete to consolidate their learning from the presentation.
Challenge: Rewrite the method after completing the evaluation. The points in the evaluation should be reflected in the improved method.
Discuss findings from the practical and then complete the end of unit assignment.
Heat can be transferred through solids by three processes: conduction, convection, and radiation. Conduction is the primary mode of heat transfer in solids.
Conduction occurs when heat is transferred from one molecule to another within a solid material without any overall movement of the material itself. This transfer of heat occurs through direct contact between neighbouring molecules in the solid. When one molecule is heated, it transfers its energy to its neighbouring molecules, causing them to vibrate more vigorously and thus increasing their temperature. This process continues throughout the solid until the heat energy has been distributed evenly.
The rate of heat conduction through a solid material depends on several factors, including the thermal conductivity of the material, the temperature difference between the two ends of the solid, and the cross-sectional area of the solid. Materials with higher thermal conductivity, such as metals, are better at conducting heat than materials with lower thermal conductivity, such as plastics or wood.
In some cases, convection can also play a role in the transfer of heat through solids. This occurs when heat is transferred from one part of a solid to another by the movement of the material itself, due to a temperature gradient. However, this is less common in solids than in liquids or gases, where convection is a more significant mode of heat transfer.
Radiation can also play a role in the transfer of heat through solids, but it is typically less significant than conduction or convection. Radiation occurs when electromagnetic waves are emitted by a warm object and absorbed by a cooler object, causing the cooler object to increase in temperature. This process can occur between two solid objects that are not in direct contact, but it is typically less efficient than conduction or convection.