Conduction, convection and radiation

• What are the three methods of energy transfer?

  Conduction, convection, and radiation
• Why are conduction and convection grouped together?

  Both require particles to transfer energy
• How is energy transferred in solids?

  By conduction
• What happens to particles when a solid is heated?

  They vibrate more
• Why is it important to use the word "more" when describing particle vibration?

  Particles already vibrate in solids
• How do particles transfer energy in a heated solid?

  By colliding with neighboring particles
• What happens to a metal rod when one end is heated?

  The other end becomes very hot
• What are conductors and insulators?

  Conductors transfer heat easily; insulators do not
• What materials are considered good conductors?

  All metals
• What materials are good insulators?

  Air, foam, plastic, rubber, and wood
• Why are metals good conductors?

  They have closely arranged atoms
• Why do insulators like air and foam transfer energy poorly?

  Particles are much further apart
• What is convection?

  Energy transfer in fluids due to particle movement
• In which states of matter does convection occur?

  Gases and liquids
• What happens to particles near a heat source in convection?

  They gain energy and move faster
• What occurs to the density of a gas or liquid when heated?

  It becomes less dense
• What is a convection current?

  A constant current of rising and falling particles
• How does heating water on a stove demonstrate conduction and convection?

  Heat transfers from the pan to the water
• What happens to the atoms in the bottom of a heated pan?

  They vibrate more and transfer energy
• How is water heated in a pan?

  By convection currents forming in the water
• Why can you touch the handle of a pan made of rubber?

  Rubber is a poor conductor of heat
• What is radiation in terms of energy transfer?

  Energy transfer without involving particles
• How does radiation differ from conduction and convection?

  Radiation does not involve particles
• What type of radiation do hot objects emit?

  Infrared radiation
• How does a hot radiator transfer energy?

  By emitting infrared waves in all directions
• What does the Sun emit besides infrared radiation?

  Visible light and other waves
• How does infrared radiation travel?

  As waves through space, which is a vacuum
• What do all objects do regarding infrared radiation?

  Emit and absorb infrared radiation
• How can infrared radiation be detected?

  Using an infrared camera
• What happens to the thermal energy store of objects when they absorb infrared radiation?

  They heat up
• How does infrared radiation work in a barbecue?

  It heats sausages as fuel burns
• What role does infrared radiation play in a toaster?

  It turns bread into toast
• Which color is the best absorber and emitter of radiation?

  Matte black
• Which color is the worst absorber and emitter of radiation?

  Silver
• Why is silver useful in some scenarios regarding radiation?

  It reflects radiation effectively
• How does silver foil help keep hot foods warm?

  It reflects emitted radiation back
• What is the purpose of a foil blanket for marathon runners?

  To reflect emitted radiation back
• How does energy transfer by heating occur?

  From a hotter region to a cooler region
• What happens to the temperature of the hotter region during energy transfer?

  The temperature of the hotter region decreases
• What happens to the temperature of the cooler region during energy transfer?

  The temperature of the cooler region increases