Chapter Menu

1
Chapter Menu
Chapter Introduction Lesson 1 Thermal Energy,
Temperature, and Heat Lesson 2 Thermal Energy
Transfers Lesson 3 Using Thermal
Energy Chapter Wrap-Up
2
Chapter Introduction

• How can thermal energy be used?

3
Chapter Introduction

• What do you think?

Before you begin, decide if you agree or disagree
with each of these statements. As you view this
presentation, see if you change your mind about
any of the statements.
4
Chapter Introduction
Do you agree or disagree?

• 1. Temperature is the same as thermal energy.
• 2. Heat is the movement of thermal energy from a
  hotter object to a cooler object.
• 3. It takes a large amount of energy to
  significantly change the temperature of an object
  with a low specific heat.

5
Chapter Introduction
Do you agree or disagree?

• 4. The thermal energy of an object can never be
  increased or decreased.
• 5. Car engines create energy.
• 6. Refrigerators cool food by moving thermal
  energy from inside the refrigerator to the
  outside.

6
Lesson 1 Reading Guide - KC
Thermal Energy, Temperature, and Heat

• How are temperature and kinetic energy related?
• How do heat and thermal energy differ?

7
Lesson 1 Reading Guide - Vocab
Thermal Energy, Temperature, and Heat

• thermal energy
• temperature
• heat

8
Lesson 1-1
Kinetic and Potential Energy

• Potential energy is stored energy due to the
  interaction between two objects.
• The potential energy plus the kinetic energy of
  an object is the mechanical energy of the object.

9
Lesson 1-2
What is thermal energy?

• Every solid, liquid, and gas is .
• Because particles are in motion, they have
  kinetic energy.
• The faster particles move, the more kinetic
  energy they have.

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Lesson 1-2
What is thermal energy? (cont.)

• The greater the average distance between
  particles, the greater the potential energy of
  the particles.
• Thermal energy is the .

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Lesson 1-2

• The potential energy of the soccer ball depends
  on the distance between the ball and Earth. The
  potential energy of the particles of matter
  depends on their distance from one another.

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Lesson 1-2
What is thermal energy? (cont.)

• Mechanical energy describes the energy of one
  object.
• Thermal energy describes the energy of the
  particles that make up a solid, liquid, or gas.

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Lesson 1-3
What is temperature?

• Scientists define temperature in terms of
  kinetic energy.
• Temperature

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Lesson 1-3
What is temperature? (cont.)
temperature from Latin temperatura, means
moderating, tempering
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Lesson 1-3
What is temperature? (cont.)

• The greater the average kinetic energy of
  particles, the .
• The particles in warmer air move at a greater
  average speed than the particles in colder air.

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Lesson 1-3
What is temperature? (cont.)
How are temperature and kinetic energy related?
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Lesson 1-3
What is temperature? (cont.)

• Temperature and thermal energy are related, but
  they are not the same.
• The particles that make up liquid and solid water
  .

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Lesson 1-3
What is temperature? (cont.)

• Thermometers are used to measure temperature.
• Common temperature scales are Celsius (C),
  Kelvin (K), and Fahrenheit (F).

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Lesson 1-4
What is heat?

• is called heat.
• All objects have thermal energy however, you
  heat something when thermal energy transfers from
  one object to another.
• The rate at which heating occurs depends on the
  difference in temperatures between the objects.

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Lesson 1-4
What is heat? (cont.)
How do heat and thermal energy differ?
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Lesson 1 - VS

• The greater the distance between two particles
  or two objects, the greater the potential
  energy.
• Heat is the movement of thermal energy from a
  warmer object to a cooler object.

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Lesson 1 - VS

• When thermal energy moves between a material and
  its environment, the materials temperature
  changes.

23
Lesson 1 - Now
Do you agree or disagree?

• 1. Temperature is the same as thermal energy.
• 2. Heat is the movement of thermal energy from a
  hotter object to a cooler object.

24
Lesson 2 Reading Guide - KC
Thermal Energy Transfers

• What is the effect of having a small specific
  heat?
• What happens to a material when it is heated?
• In what ways can thermal energy be transferred?

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Lesson 2 Reading Guide - Vocab
Thermal Energy Transfers

• thermal expansion
• thermal contraction
• convection
• convection current

• radiation
• conduction
• thermal conductor
• thermal insulator
• specific heat

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Lesson 2-1
How is thermal energy transferred?

• Thermal energy is transferred in three ways.

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Lesson 2-2
Radiation

• is called radiation.
• Radiation is the only way thermal energy can
  travel from the Sun to Earth, because space is a
  vacuum.
• Radiation also transfers thermal energy through
  solids, liquids, and gases.

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Lesson 2-2
Radiation (cont.)
vacuum Science Use a space that contains little
or no matter Common Use a device for cleaning
carpets and rugs that uses suction
29
Lesson 2-3
Conduction

• When particles with different kinetic energies
  collide, the particles with higher kinetic energy
  transfer energy to particles with lower kinetic
  energy.
• is called conduction.
• Conduction continues until the thermal energy of
  all particles in contact is equal.

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Lesson 2-3
Conduction (cont.)

• The hot air transfers thermal energy to, or
  heats, the cool lemonade by conduction.
• Eventually the kinetic thermal energy and
  temperature of the air and the lemonade will be
  equal.

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Lesson 2-3
Conduction (cont.)

• A thermal conductor is a
• A thermal insulator is a

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Lesson 2-3
Conduction (cont.)

• is called specific heat.
• Waters high specific heat helps prevent your
  body from overheating.
• Changing the temperature of a material with a low
  specific heat is easier than to change the
  temperature of a material with a high specific
  heat.

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Lesson 2-3

• In a hot car, the temperature of thermal
  conductors, such as the safety-belt buckles,
  increases more quickly than the temperature of
  thermal insulators, such as the seat material.

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Lesson 2-3
Conduction (cont.)
What does it mean if a material has a low
specific heat?
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Lesson 2-4
Thermal Expansion and Contraction

• Thermal contraction is a
• Thermal expansion is an
• Thermal expansion and contraction are most
  noticeable in gases, less noticeable in liquids,
  and the least noticeable in solids.

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Lesson 2-4
Thermal Expansion and Contraction (cont.)
What happens to the volume of a gas when it is
heated?
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Lesson 2-5
Convection

• Convection is the .
• Convection only occurs in fluids.

convection from Greek convectionem, means the
act of carrying
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Lesson 2-5

• This cycle of cooler water sinking and forcing
  warmer water upward is an example of convection.

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Lesson 2-5
Convection (cont.)
What are the three processes that transfer
thermal energy?
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Lesson 2-5
Convection (cont.)

• is a convection current.
• Convection currents circulate the water in
  Earths oceans and other bodies of water.

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Lesson 2-5
Convection Currents in Earths Atmosphere
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Lesson 2 - VS

• When a material has a low specific heat,
  transferring a small amount of energy to the
  material increases its temperature significantly.

43
Lesson 2 - VS

• Thermal energy can be transferred through
  radiation, conduction, or convection.

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Lesson 2 - VS

• When a material is heated, the thermal energy of
  the material increases and the material expands.

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Lesson 2 - Now
Do you agree or disagree?
3. It takes a large amount of energy to
significantly change the temperature of an object
with a low specific heat. 4. The thermal energy
of an object can never be increased or decreased.
46
Lesson 3 Reading Guide - KC
Using Thermal Energy

• How does a thermostat work?
• How does a refrigerator keep food cold?
• What are the energy transformations in a car
  engine?

47
Lesson 3 Reading Guide - Vocab
Using Thermal Energy

• heating appliance
• thermostat
• refrigerator
• heat engine

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Lesson 3-1
Thermal Energy Transformations

• Thermostats transform thermal energy into
  mechanical energy that switch heaters on and off.
• Even though many devices transform energy from
  one form to another or transfer energy from one
  place to another, the total amount of energy does
  not change.

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Lesson 3-2
Heating Appliances

• is a heating appliance.
• Curling irons, coffeemakers, and clothes irons
  are some examples of heating appliances.

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Lesson 3-3
Thermostats

• A thermostat is a .

thermostat from Greek therme, meaning heat and
statos, meaning a standing
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Lesson 3-3
Thermostats (cont.)

• Most thermostats contain a bimetallic coil made
  of two types of metal joined together and bent
  into a coil.
• The metal on the inside of the coil expands and
  contracts more than the metal on the outside of
  the coil.
• When a room warms or cools, the thermal energy
  causes the bimetallic coil to uncurl slightly or
  tighten, which turns the furnace off or on.

52
Lesson 3-3
Thermostats (cont.)
How does the bimetallic coil in a thermostat
respond to heating and cooling?
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Lesson 3-4
Refrigerators

• is called a refrigerator.
• In a refrigerator, a coolant is pumped through
  pipes on the inside and the outside of the
  refrigerator.

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Lesson 3-4

• Coolant in a refrigerator moves thermal energy
  from inside to outside the refrigerator.

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Lesson 3-4

• The coolant, which begins as a liquid, passes
  through an expansion valve and cools.

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Lesson 3-4

• As the cold gas flows through pipes inside the
  refrigerator, it absorbs thermal energy from the
  refrigerator compartment and vaporizes.

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Lesson 3-4
Refrigerators (cont.)
How does a refrigerator keep food cold?
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Lesson 3-5
Heat Engines

• A heat engine is a
• When a heat engine converts thermal energy into
  mechanical energy, the mechanical energy moves
  the vehicle.
• Most cars, buses, boats, trucks, and lawn mowers
  use a type of heat engine called an internal
  combustion engine.

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Lesson 3-5
Internal Combustion Engine
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Lesson 3-5
Internal Combustion Engine
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Lesson 3-5
Heat Engines (cont.)
What is one form of energy that is output from a
heat engine?
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Lesson 3 - VS

• A bimetallic coil inside a thermostat controls a
  switch that turns a heating or cooling device on
  or off.

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Lesson 3 - VS

• A refrigerator keeps food cold by moving thermal
  energy from the inside of the refrigerator out to
  the refrigerators surroundings.

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Lesson 3 - VS

• In a car engine, chemical energy in fuel is
  transformed into thermal energy. Some of this
  thermal energy is then transformed into
  mechanical energy.

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Lesson 3 - Now
Do you agree or disagree?
5. Car engines create energy. 6. Refrigerators
cool food by moving thermal energy from inside
the refrigerator to the outside.
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Chapter Review Menu
Key Concept Summary Interactive Concept
Map Chapter Review Standardized Test Practice
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The BIG Idea

• Thermal energy can be transferred by conduction,
  radiation, and convection. Thermal energy also
  can be transformed into other forms of energy and
  used in devices such as thermostats,
  refrigerators, and automobile engines.

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Key Concepts 1
Lesson 1 Thermal Energy, Temperature, and Heat

• The temperature of a material is the average
  kinetic energy of the particles that make up the
  material.
• Heat is the movement of thermal energy from a
  material or area with a higher temperature to a
  material or area with a lower temperature.
• When a material is heated, the materials
  temperature changes.

69
Key Concepts 2
Lesson 2 Thermal Energy Transfers

• When a material has a low specific heat,
  transferring a small amount of energy to the
  material increases its temperature significantly.
• When a material is heated, the thermal energy of
  the material increases and the material expands.
• Thermal energy can be transferred by conduction,
  radiation, or convection.

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Key Concepts 3
Lesson 3 Using Thermal Energy

• The two different metals in a bimetallic coil
  inside a thermostat expand and contract at
  different rates. The bimetallic coil curs and
  uncurls, depending on the thermal energy of the
  air, pushing a switch that turns a heating or
  cooling device on or off.
• A refrigerator keeps food cold by moving thermal
  energy from inside the refrigerator out to the
  refrigerators surroundings.
• In a car engine, chemical energy in fuel is
  transformed into thermal energy. Some of this
  thermal energy is then transformed into
  mechanical energy.