Temperature, Thermal Energy, and Heat

1
Table of Contents

• Temperature, Thermal Energy, and Heat
• The Transfer of Heat
• Thermal Energy and States of Matter
• Uses of Heat

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Temperature
Temperature, Thermal Energy and Heat

• Temperature is a measure of the average kinetic
  energy of the individual particles in matter.

3
Temperature
Temperature, Thermal Energy and Heat

• Temperature changes cause the level of the liquid
  inside a thermometer to rise and fall.

4
Temperature Scales
Temperature, Thermal Energy and Heat

• The three common scales for measuring temperature
  are the Kelvin, Fahrenheit, Celsius, and scales.
  (KFC)
• The ones used more often in science are the
  Celsius and Kelvin Scale.
• These two scales are similar but 0 on the Kelvin
  scale is Absolute Zero. The coldest temperature
  possible. This is -273.14 degrees Celsius

5
Converting Units
Temperature, Thermal Energy and Heat

• To convert a Fahrenheit temperature to a Celsius
  temperature, use the following formula
• ºC 5/9 (ºF 32)
• For example, if the temperature in your classroom
  is 68ºF, what is the temperature in degrees
  Celsius?
• ºC 5/9 (68 32)
• ºC 5/9 X 36
• ºC 20
• The temperature of your classroom is 20ºC.

6
Converting Units
Temperature, Thermal Energy and Heat

• Practice Problem
• While at the beach, you measure the ocean
  temperature as 77ºF. What is the temperature of
  the ocean in degrees Celsius?

• 25ºC

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Specific Heat
Temperature, Thermal Energy and Heat

• The specific heat of three different materials
  was measured. These data are shown in the graph.

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Specific Heat
Temperature, Thermal Energy and Heat

• Reading Graphs
• What three materials are compared in the graph?

• Water, sand, and iron

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Specific Heat
Temperature, Thermal Energy and Heat

• Interpreting Data
• About how much heat is required to raise 1 kg of
  water by 1 K?

• About 4,200 J would be required

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Specific Heat
Temperature, Thermal Energy and Heat

• Drawing Conclusions
• According to the graph, which material requires
  more heat to raise its temperature by 1 K, iron
  or sand?

• Sand

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Specific Heat
Temperature, Thermal Energy and Heat

• A material with a high specific heat can absorb a
  great deal of thermal energy without a great
  change in temperature.

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Comparing and Contrasting
Temperature, Thermal Energy and Heat

• As you read, compare and contrast temperature,
  thermal energy, and heat by completing a table
  like the one below.

Energy Measured
Units
Average kinetic energy of particles
Fahrenheit or Celsius degrees, kelvins
Temperature
Total energy of all particles in an object
Thermal Energy
Joules
Heat
Energy transferred
Joules
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Temperature
Temperature, Thermal Energy and Heat

• Click the Video button to watch a movie about
  temperature.

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Links on Temperature and Heat
Temperature, Thermal Energy and Heat

• Click the SciLinks button for links on
  temperature and heat.

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End of SectionTemperature, Thermal Energy, and
Heat
16
Heat Moves One Way
- The Transfer of Heat

• If two objects have different temperatures, heat
  will flow from the warmer object to the colder
  one.

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Insulators
- The Transfer of Heat

• Air between the panes of this window acts as an
  insulator to slow the transfer of heat.

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Identifying Main Ideas
- The Transfer of Heat

• As you read the section How Is Heat
  Transferred?, write the main idea in a graphic
  organizer like the one below. Then write three
  supporting details that further explain the main
  idea.

Main Idea
Heat can be transferred in three ways.
Detail
Detail
Detail
Conduction transfer of heat between particles
without the movement of matter
Convection transfer of heat by the movement of
currents in a fluid
Radiation transfer ofenergy by electromagnetic
waves
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Links on Heat Transfer
- The Transfer of Heat

• Click the SciLinks button for links on forms of
  heat transfer.

20
Insulators
- The Transfer of Heat

• Click the Video button to watch a movie about
  insulators.

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End of SectionThe Transfer of Heat
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States of Matter
Thermal Energy and States of Matter

• Most matter on Earth can exist in three
  statessolid, liquid, and gas.

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Changes of State
Thermal Energy and States of Matter

• Matter can change from one state to another when
  thermal energy is absorbed or released.

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Thermal Expansion
Thermal Energy and States of Matter

• As the thermal energy of matter increases, its
  particles spread out and the substance expands. A
  bimetallic strip in a thermostat contracts or
  expands depending on whether it is cooled or
  warmed.

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Building Vocabulary
Thermal Energy and States of Matter

• Using a word in a sentence helps you think about
  how best to explain the word. After you read the
  section, reread the paragraphs that contain
  definitions of Key Terms. Use the information you
  have learned to write a meaningful sentence for
  each Key Term.

Key Terms
Examples
state
Water can exist in three different states, or
forms.
If vaporization takes place at the surface of a
liquid, it is called evaporation.
change of state
The physical change from one state of matter to
another is called a change of state.
At higher temperatures, vaporization can occur
below the surface of a liquid as well. This
process is called boiling.
melting
The change of state from a solid to a liquid is
called melting.
A change from the gas state to the liquid state
is called condensation.
freezing
The change of state from a liquid to a solid is
called freezing.
The expanding of matter when it is heated is
known as thermal expansion.
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Links on Changes of State
Thermal Energy and States of Matter

• Click the SciLinks button for links on changes of
  state.

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End of SectionThermal Energy and States of
Matter
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External Combustion Engines
- Uses of Heat

• Engines that burn fuel outside the engine in a
  boiler are called external combustion engines.

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Internal Combustion Engines
- Uses of Heat

• Most automobiles use four-stroke engines. These
  four strokes occur repeatedly in each of the
  engines cylinders.

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Four-Stroke Engine Activity
- Uses of Heat

• Click the Active Art button to open a browser
  window and access Active Art about four-stroke
  engines.

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Cooling Systems
- Uses of Heat

• A refrigerator is a device that transfers thermal
  energy from inside the refrigerator to the room
  outside.

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Sequencing
- Uses of Heat

• A sequence is the order in which a series of
  events occurs. As you read, make a cycle diagram
  that shows how refrigerators work. Write each
  phase of the cooling systems cycle in a separate
  circle.

How Refrigerators Work
Refrigerant absorbs heat.
Expansion valve decreases refrigerants
temperature.
Compressor increases refrigerants temperature.
Refrigerant releases heat.
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End of SectionUses of Heat
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Graphic Organizer
Heat
is the transfer of
Thermal energy
by
Convection
Conduction
Radiation
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End of SectionGraphic Organizer