Heat transfer and the particle model
The Particle Model
1. All __________ is made up of tiny _________ too small to see
2. There is __________ between the particles
3. Particles are always ___________ (vibrating)
4. At _________temperatures, particles move faster
Thermal energy in moves in three ways
1. C_________
2. C_________
3. R_________
Figure 1 Three type of heat transfer
Conduction
• Conduction is the transfer of _________ from one particle of ________to
another by _________ particle to _________ contact.
• Occurs primarily in _________because the particles are tightly
_________ together.
• The particles themselves do not change position.
Figure 2 Conduction
1. Fast-moving particles (lots of energy) collide with neighbouring particles
2. This gives them more ___________ making them vibrate faster
3. This continues along the _______ of the solid until _____ the particles are ___________with lots of
energy
Convection
• The transfer of _________ energy (heat) through the bulk
movement of matter.
• Occurs in __________ (liquids & gases).
• Thermal energy is carried by the particles as they move
from one location to another because of a _________ in
_____________.
• Convection creates currents
• “____” particles are more spaced out and _______
• “_______” particles are closer together so they are
more ________, and fall
•
Density- a measure of how much mass is in a given volume.
Radiation
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Radiation is the transfer of (thermal) energy by
_________________ _____________.
Radiation does _______require _________ to transfer
thermal energy.
Two objects do not need to __________ in order for
radiation to transfer heat between them
Heat radiation can travel through a ___________ – this is how the heat from the Sun reaches us.
All objects (matter) can transfer some heat by _____________ e.g. you feel the radiation of thermal
energy from a camp fire
The hotter the object is the ___________ heat it _______________.
The radiation itself is not hot, but when it is _____________by an object it causes the particles to
vibrate more rapidly, thus heating it.
What type of heat transfer is happening at each one of the labels in the diagram below:
W
X
Y
Z