Conduction and Convection Flashcards
What is conduction?
The process where vibrating particles transfer energy to neighboring particles
What does conduction mainly occur in?
Solids
What happens when heat is conducted throughout the solid?
- Gradually some of the extra kinetic energy is passed all the way through the solid
- This causes a rise in temperature at the far side of the object
- The heat radiating from the surface is increased
Where is conduction fastest?
In denser solids
Why is conduction faster in denser solids?
The particles are closer together and will collide more often and pass energy between them
What happens to materials with larger spaces between their particles?
- They conduct energy slower
- They can be used as insulators
Why do metals conduct heat so well?
Because electrons are free to move inside the metal
What is convection?
Where energetic particles move away from hotter regions to cooler regions, taking free energy with them
What does convection occur in?
Liquids and gases
Why can’t convection happen in solids?
Because the particles can’t move freely
What appliances use convection?
Immersion heaters in:
- Kettles
- Hot water tanks
- Convection heaters
In immersion heaters, what do you end up with?
- Convection current goes up, around and down
- The heat energy is circulated through the water
Where is convection most efficient?
Round / squarish containers
What are the convection currents based on?
Changes in density
