Conduction, Convection. Radiation

• What happens to an object's thermal energy store when it is heated?

  Energy is transferred to its thermal energy store.
• What are the three ways heat can be transferred depending on the medium involved?

  Conduction, convection, and radiation.
• How is heat transferred in solids?

  By conduction.
• How is heat transferred in fluids?

  By convection.
• How is heat transferred through empty space?

  In the form of radiation.
• What is the key idea behind conduction?

  Vibrating particles transfer energy to neighboring particles.
• What happens when one end of a piece of metal is heated with a Bunsen burner?

  Energy is transferred to the kinetic energy store of the particles at that end.
• What occurs to the particles in a metal when they are heated?

  They vibrate faster and collide with neighboring particles more often.
• How does energy transfer through a piece of metal occur?

  Through a series of collisions between vibrating particles.
• Why does conduction occur mainly in solids?

  Because the particles in a solid are held closely together, allowing for many collisions.
• What is thermal conductivity?

  It is how well objects transfer energy by conduction.
• Which materials have high thermal conductivity?

  Metals.
• Why are plastics used as insulators?

  Because they have low thermal conductivity.
• What is the primary method of heat transfer in fluids?

  Convection.
• What happens to particles in fluids when they are heated?

  They gain kinetic energy and move around faster.
• What occurs to the density of heated fluid particles?

  They become less dense and rise above cooler particles.
• What is a convection current?

  A cycle where warmer particles rise and cooler particles sink.
• Where can convection currents be observed in real life?

  In oceans and inside buildings with radiators.
• How can convection be reduced?

  By stopping the free flow of fluids, such as using a blanket.
• What do conduction and convection have in common?

  Both involve particles gaining kinetic energy.
• How is heat energy transferred without particles?

  Through radiation, specifically by infrared waves.
• What do all objects do in terms of radiation?

  They constantly absorb and emit radiation.
• What happens to the amount of radiation emitted by an object as its temperature increases?

  The hotter the object, the more radiation it emits.
• Why does it feel hot to put your hand over a barbecue?

  Because the hot metal and coal emit infrared radiation absorbed by your hand.
• What type of radiation is specifically mentioned in the context of heat transfer?

  Infrared radiation.
• What is the electromagnetic spectrum?

  A range of all types of electromagnetic radiation, including infrared waves.
• What are the three methods of heat transfer and their characteristics?

  • Conduction: Transfer of heat through direct contact in solids.
  • Convection: Transfer of heat in fluids (liquids and gases) through the movement of particles.
  • Radiation: Transfer of heat through infrared waves without the need for a medium.
• Describe the process of convection in a fluid when heated.

  1. Particles near the heat source gain kinetic energy and spread out.
  2. Less dense particles rise while cooler, denser particles sink.
  3. This creates a convection current that continues as long as the fluid is heated.
• What is the difference between conduction and convection?

  • Conduction: Energy is transferred between particles without their movement.
  • Convection: Energy is transferred through the movement of particles in a fluid.
• How does temperature affect radiation emission from objects?

  • Higher temperatures result in increased radiation emission.
  • All objects continuously absorb and emit radiation simultaneously.