Revision as of 10:00, 19 February 2012

Outcomes

• Pupils understand that thermal energy is transferred in three ways: conduction, convection and radiation.
• Pupils understand the process of evaporation as a decrease in thermal energy.

Specification References

4.6 recall that energy transfer may take place by conduction, convection and radiation

Starter

Main Body of Lesson

• Emphasise to pupils that "cold" doesn't move - thermal energy always moves from higher concentration (hot objects) to lower concentration (cold objects). You can draw parallels with biological examples that they may be familiar with (e.g. osmosis).
• Explain the processes of conduction, convection and radiation using heat transfers circus.
• Show pupils demonstrations of conduction, convection and radiation.
• Explain the process of evaporation as a decrease in average kinetic energy.
• Show pupils evaporation demonstration.

Practicals/Demonstrations

Conduction demonstrations

• Wood/aluminium plates (identical in appearance) with ice cubes - one melts very quickly, one very slowly.
• Rods of different metals (e.g. copper, aluminium) with embedded thermochromic thermometers (or alternatively, covered in wax) can show the progress of conduction.

Convection demonstrations

• Convection tubes; one with potassium permanganate and spirit burner; one with water and glitter.
• Smaller convection tube with can be "operated" by heat from a pupil's hand.

Radiation demonstrations

• Lesley's Cube
• Infrared thermometer
• Thermographic images

Evaporation demonstration

• Dab a small amount of alcohol from a cotton bud onto the back of pupils' hands.

Plenary

Homework

Additional Information

Resources Required

Skills Addressed

• Spear fishing

Safety/Hazards

• Flying popcorn could injure.
• Hot popcorn is hot.
• Pupil may choke on popcorn.

Energy Outline

Energy (3rd Form)