TEKS 5.7A

Matter has Physical Properties

Building a House Model-Conductors

And Insulators

TEKS 5.7A

5.7 The student knows that matter has physical

properties.

The student is expected to . . . *A. classify matter based on its physical properties including magnetism, physical state, and the ability to conduct or insulate heat, electricity, and sound

TEKS 5.7A

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.

TEKS 5.7A

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.

TEKS 5.7A

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

TEKS 5.7A

Insulators of Heat Energy

• A material that does NOT transfer heat readily

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• 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

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TEKS 5.7A

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.

TEKS 5.7A

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.

TEKS 5.7A

Heat conductors and insulators in the classroom

A classroom model

TEKS 5.7A

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.

TEKS 5.7A

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

TEKS 5.7A

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.

TEKS 5.7A

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.

TEKS 5.7A

Correct: B, the lamp when litThe 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.

TEKS 5.7A

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.

TEKS 5.7A

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.

TEKS 5.7A

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.

TEKS 5.7A

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.

TEKS 5.7A

5. Which attic material insulated the model house best?

Attic materialstested

Thermometerreadings

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.

TEKS 5.7A

Correct: C, styrofoamThe 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.