Modes of Heat Transfer

1. ENERGY
CONSERVATION & TRANSFER
Explain how the properties of
some materials change as a result
of heating and cooling.

2. CLEAR LEARNING GOAL
AS A STUDENT I WILL BE ABLE TO IDENTIFY AND
EXPLAIN THE DIRECTION THAT HEAT TRAVELS
AMONG DIFFERENT OBJETS.

3. Heat transfers throughout our
environment all the time. Wherever you
are, you are aware of things that are
warm or cool. You also notice when
things are getting hotter or colder.

4. If you dive into a swimming pool or walk
barefoot on a sidewalk in the summer
you are feeling the effects of heat
transfer.
Transfer- Transfer is the movement from one
place to another!

5. • Energy is what makes things happen.
• All materials are made of tiny particles called
molecules.
• Molecules are always moving. These Molecules are in
motion.
• The movement creates heat.
• The amount of heat depends on how fast the molecules
move.
• As the molecules move faster, they take up more space
and make the object expand.
Heat Energy

6. IMPORTANT!!!
Heat transfer ALWAYS follows the following rule
The direction of transfer always
occurs from the hotter object to
the cooler object.

7. CLEAR LEARNING GOAL
AS A STUDENT I WILL BE ABLE TO IDENTIFY AND
EXPLAIN THE DIFFERENCES BETWEEN
RADIATION, CONVECTION, AND CONDUCTION.

8. HEAT TRANSFER
In our environment, heat transfers to
another object in three different ways.
They are:
1. Radiation
2. Conduction
3. Convection
* Remember all three ways follow the direction
rule from hotter to colder.

9. Graphic Organizer

10. CONDUCTION
Conduction is the transfer of thermal energy (heat)
between things that are touching.
EXAMPLE: Placing a spoon in a bowl of hot soup
results is a hot spoon.
OTHER EXAMPLES?

11. CONVECTION
Convection is the transfer of thermal energy (heat)
through the up and down movement of liquids or
gasses.
Hot liquids/gasses rise and cooler liquids/gasses sink
•This constant movement of up and down allows the
liquid or gas to heat.
EXAMPLE: Boiling Water, Air Masses, Hot Air Balloons

12. RADIATION
RADIATION is the transfer of thermal energy (heat)
through open space.
Objects/liquids/gasses do not need to be touching to
transfer the heat.
EXAMPLE: Sun warming the Earth, Warming Hands
over Fire, Heat lamps at fast food restaurant.

13. JOURNAL RESPONSE
In your Science Journal, Draw a
sketch of the following
diagram, identify each method
of heat transfer, label the
diagram, and write three to
four sentences explaining your
reasoning.

14. CLEAR LEARNING GOAL
AS A STUDENT I WILL BE ABLE TO IDENTIFY
AND EXPLAIN HEAT TRANSFER THROUGH
CONDUCTION.

15. CONDUCTION
Conduction is the transfer of thermal energy (heat)
between things that are touching.
EXAMPLE: Placing a spoon in a bowl of hot soup
results in a hot spoon.
OTHER EXAMPLES?
Some objects/materials allow heat to transfer
through them more quickly than others. We consider
these good conductors.

16. CONDUCTION
Two objects must touch or have
direct contact!!!
ONLY HAPPENS IN THE EVENT OF
HEAT TRAVELING THROUGH
SOLIDS

17. CONDUCTION
When you touch one hot surface
to another, the hot molecules
bump into the other molecules
which makes them start to move
faster.
An object gets hotter from the
movement of the molecules.

18. Conduction
When you heat a metal strip at one end, the heat travels to the other
end.
As you heat the metal, the molecules vibrate, these vibrations make the
adjacent molecules vibrate, and so on and so on, the vibrations are passed
along the metal and so is the heat. We call this?
Conduction

19. Conduction
 All solid objects conduct heat, some are better
conductor than others.
 Metals are good conductors.

20. Journal Response Question
Thinking about your own house, when do you
use conduction? Draw a diagram that shows
when you use conduction, label the parts,
and explain how and why your diagram is an
example of conduction.

21. CONVECTION
Convection is the transfer of thermal energy (heat)
through the up and down movement of liquids or
gasses.
Hot liquids/gasses rise and cooler liquids/gasses sink
•This constant movement of up and down allows the
liquid or gas to heat.
EXAMPLE: Boiling Water, Air Masses, Hot Air Balloons

22. CONVECTION
CONVECTION OCCURS IN THE
HEATING OF LIQUIDS OR GASSES
ONLY
DOES NOT OCCUR IN THE TRANSFER
OF HEAT WITHIN SOLIDS

23. CONVECTION
As molecules heat up, the heat makes
the molecules move more rapidly and
expand.
Which creates currents in liquids or
gases – hot air rises and cold air
sinks.

24. EXAMPLES

25. Cold air sinks
Where is the
freezer
compartment put in
a fridge?
Freezer
compartment
It is put at the top,
because cool air
sinks, so it cools the
food on the way
down.
It is warmer at
the bottom, so
this warmer air
rises and a
convection
current is set up.

26. Journal Response Question
IN THREE OR MORE SENTENCES EXPLAIN THE PROCESS OF
CONVECTION AND DRAW A PICTURE THAT SHOWS AN EXAMPLE OF
CONVECTION.

27. CLEAR LEARNING GOAL
AS A STUDENT I WILL BE ABLE TO IDENTIFY AND
EXPLAIN THE HEAT TRANSFER PROCESS
KNOWN AS RADIATION.

28. Simple Radiation Demonstration
To see the effects of radiation, students will need to coat the tip of a
toothpick with a bit of wax as it melts and runs down the side of the
candle. If they let the wax harden for a few moments, they can then
move the toothpick slowly toward the flame. They must, however,
approach the flame from below, and they should not let the wax tip
touch the flame. Rather, when the tip gets a centimeter or two from
the flame, they should see the wax begin to melt. Since the tip is not
touching the flame, the wax cannot be melting due to conduction.
Since the tip is below the flame, it cannot be melting due to
convection. Instead, the wax melts because of the heat radiated from
the flame.

29. RADIATION
RADIATION is the transfer of thermal energy
(heat) through open space.
Objects/liquids/gasses do not need to be
touching to transfer the heat.
EXAMPLE: Sun warming the Earth, Warming
Hands over Fire, Heat lamps at fast food
restaurant.

30. RADIATION
Release of invisible heat energy
waves from the sun or fire.
No movement of molecules to
transfer heat.

31. RADIATION
When the radiant energy from the sun
hits the earth, the earth soaks up the
energy and changes it into heat

32. Journal Response
Draw a picture of radiation and explain the process in
three or more sentences. BE DESCRIPTIVE.

34. CLEAR LEARNING GOAL
AS A STUDENT I WILL BE ABLE TO IDENTIFY AND
EXPLAIN THE DIFFERENCES BETWEEN
MATERIALS THE ARE CONDUCTORS AND
INSULATORS.

35. CONDUCTORS & INSULATORS
Some objects/materials allow heat to transfer through them more quickly
than others. We consider these good conductors.
Conductor- heat flows through conductors. (The
heat flows along all the molecules!)
Insulator An insulator is a material that partially or
completely blocks the flow of heat. (They trap heat in
one spot!)

36. Conductor!
A material in which molecules are able to
move easily is a conductor.
 The best electrical conductors are metals.
Example: Metal pot handle

37. CONDUCTORS
Objects that allow heat to flow
through them. Conductors are usually
made of metal. Copper, aluminum,
silver, and gold are good conductors.
 A conductor is the opposite of an insulator.

38. INSULATOR
An insulator is a material, usually non-
metallic, that partially or completely blocks
the flow of heat. Plastic, rubber, leather,
glass, and ceramic are good insulating
materials.
 An insulator is the opposite of a conductor

39. Journal Response Question
IN THREE OR MORE SENTENCES EXPLAIN HOW YOU CAN
TELL IF AN OJBECT IS A CONDUCTOR OR INSULATOR.
ADDITIONALLY, WRITE 3 EXAMPLES OF CONDUCTORS AND 3
EXAMPLES OF INSULATORS THAT WERE NOT USED IN THE
LAB

40. CLEAR LEARNING GOAL
AS A STUDENT I WILL BE ABLE TO IDENTIFY
MATERIALS THAT COULD BE USED AS
INSULATORS AND CONDUCTORS

41. HEAT TRANSFER
In our environment, heat transfers to
another object in three different ways.
They are?
* Remember all three ways follow the direction
rule from hotter to colder.

42. CONDUCTORS & INSULATORS
Some objects/materials allow heat to transfer through them more quickly
than others. We consider these good conductors.
Conductor- heat flows through conductors. (The
heat flows along all the molecules!)
Insulator An insulator is a material that partially or
completely blocks the flow of heat. (They trap heat in
one spot!)

43. CONDUCTORS
Certain materials are conductors. These items will trap heat and
allow things to stay WARM!
 Copper
 Aluminum
 Platinum
 Gold
 Silver
 Water
 People and Animals
 Trees

44. INSULATORS
CERTAIN MATERIALS ARE CONSIDRED INSULATORS. THESE ITEMS
ARE GOOD FOR KEEPING THINGS COOL!
 Glass
 Porcelain
 Plastic
 Rubber
 Wood
 Foam