Conductors & insulators

Conductors & insulators

1. TEKS 5.5A
Physical Properties of Matter
Building a House Model-
Conductors
And
Insulators

2. 5.5 The student knows that matter has measurable
physical properties and those properties determine
how matter is classified, changed, and used.
The student is expected to . . .
*A. classify matter based on physical properties including
mass, magnetism, physical state (solid, liquid, and gas),
relative density (sinking and floating), solubility in water,
and the ability to conduct or insulate thermal energy, or
electric energy

3. Heat Energy
•Heat moves from areas of high temperature to
areas of low temperature.

•When two bodies of different temperatures come
into contact, they will exchange heat energy until
the temperature of both is made the same.
•The amount of energy transferredtransferred is the
amount of heat exchanged.

4. Temperature
•Temperature measures the
physical property of ‘how
hot’ or ‘how cold’ material
is
•Celsius is the common SI
unit for temperature
measurement. ° C
•Thermometers are the
scientific tools used to
measure temperature.

5. Conductors of Heat Energy
•Materials that DO transfer heat energy from
higher temperature to lower temperature areas.
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• Examples
–materials made of metal and glass
Conduction means allowing the transfer of heat from a
higher temperature area to a lower temperature area.
Heat energy flow

6. Insulators of Heat Energy
•A material that does NOT transfer heat readily
*************************************************************************************************************************************
•Examples
–materials made of rubber, wood, cloth
–materials that have air pockets
Insulation means providing a barrier to the flow of
energy, in this case, heat.
Heat energy
I
n
s
u
l
a
t
o
r

7. Heat insulation is also called
thermal insulation
The house insulation in the walls and attic will slow
down the transfer of heat. In cold weather, inside a
warm house will be warmer than the outside
temperature. In hot weather, inside a cool house will
be cooler than the outside temperature.
The blanket keeps body heat (heat energy) close to
the boy. Heat energy is not transferred into the
surrounding air.
The styrofoam cup slows down heat transfer. A cold
drink in the cup will stay colder than the surrounding
air. A hot drink in the cup will stay hotter than the
surrounding air
.

8. Practice your learning
Conductors
•Describe conductors.
•Give an example of a
conductor.
•Describe a practical
use of a heat
conductor.
Insulators
•Describe insulators.
•Give an example of an
insulator.
•Describe a practical
use of a heat
insulator.

9. Heat conductors and
insulators in the classroom
A classroom model

10. Students are building a model of a
house using a cardboard box and
other common materials. They will
test the insulating properties of
materials that could be used in the
attic of the model.

11. 1. Choose the insulating material to use in
the attic of the model that will keep the
house the coolest.
A. Aluminum
foil
D. Glass plate

C.Styrofoam
B. Metal
screen

12. Correct:
Styrofoam is a good insulator and will not conduct
heat. The styrofoam will not allow much heat
energy from the lamp to transfer to the attic.
C.Styrofoam
Incorrect choices:
Metals, like aluminum and screens, and glass
plates are poor heat insulators, but good heat
conductors. These materials will allow the heat
energy from lamp to transfer to the attic.

13. 2. The primary heat energy source for the
model house system is
A. the classroom window.
B. the lamp when lit.
C. the air in the room.
D. the outside temperature.

14. Correct: B, the lamp when lit
The lamp when turned on and aimed at the roof of
the model house supplies the heat energy.
Incorrect choices:
A. Classroom window is probably too far from
model.
B. Room temperature air would not provide any
additional heat to the model.
C. Since the model is constructed indoors, the
outside temperature would not affect it.

15. 3. Materials are considered heat insulators
when they
A.change heat to light.
B.transfer heat energy easily.
C.make their own heat.
D. help block the transfer of heat.

16. Correct: D, when they block the transfer of
heat
Materials that are insulators do not let heat energy
pass through them easily.
Incorrect choices:
A. Heat energy is not being changed to light.
B. Materials that are heat conductors let this form
of energy pass through them easily.
C. Insulators are not the source of heat energy.

17. 4. Which statement best describes the
cardboard house model?
A. The model is built to demonstrate electric
conductors.

B. The model shows materials students
should not use.
C. Melting of the model house is a safety
problem.
D. In the natural world, solar energy would
provide the heat.

18. Correct: D, the lamp is a representation of
the Sun and solar energy
Incorrect choices:
A.The purpose of building the model is to test
materials for heat insulation not electricity
conduction.
B.The materials are appropriate for student use.
C.If safety rules are not observed, burning, not
melting, could be a problem.

19. 5. Which attic material insulated the model
house best?
Attic materials
tested
Thermometer
readings
Aluminum foil 35ºC
Metal screen 30ºC
Styrofoam 20ºC
Glass plates 25ºC
A thermometer placed on
the roof reads 35º C.
A.Aluminum foil
B.Metal screen
C.Styrofoam
D.Glass plates
A second thermometer is
placed inside the house.

20. Correct: C, styrofoam
The temperature readings with the thermometer
placed inside the house indicated when styrofoam
was used as insulation the temperature was 20ºC-
the lowest recorded temperature. Materials that are
insulators do not let heat energy pass through them
easily.
Incorrect choices:
All the other materials had recorded temperatures of higher
than 20º C. The best insulator should keep the inside of the
house the coolest (the lowest temperature). 20º was also
lower than the temperature of the heat from the lamp as
recorded with the roof thermometer.