# Thermal Energy and Heat (PowerPoint)

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```					Thermal Energy and Heat

In Hot Water
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Chapter Project, page 175 Yes, you are going to do it!

Temperature, Thermal Energy, and Heat
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What are the three common temperature scales? How is thermal energy related to temperature and heat? What does having a high specific heat mean?

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Temperature, Thermal Energy, and Heat
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How Cold is the Water? Discover Activity, page 176

Temperature, Thermal Energy, and Heat
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Temperature: a measure of the average kinetic energy of the individual particles in matter

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Measuring Temperature

Temperature, Thermal Energy, and Heat
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Temperature Scales The three common scales for measuring temperature are the Fahrenheit, Celsius, and Kelvin scales.

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Temperature, Thermal Energy, and Heat
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Fahrenheit Scale: the most common temperature scale in the United States Freezing Point of water—32oF Boiling Point of water—212oF

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Temperature, Thermal Energy, and Heat
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Celsius Scale: the scale to measure temperature used in most other countries Freezing Point of water—0oC Boiling Point of water—100oC

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Temperature, Thermal Energy, and Heat
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Kelvin Scale: the common scale used in physical science Freezing Point of water—273 K Boiling Point of water—373 K

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Temperature, Thermal Energy, and Heat
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Absolute Zero: zero on the Kelvin scale where no more thermal energy can be removed from matter

Temperature, Thermal Energy, and Heat
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Thermal Energy and Heat Thermal Energy

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Heat
Heat is thermal energy moving from a warmer object to a cooler object.

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Temperature, Thermal Energy, and Heat
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Specific Heat: the amount of energy required to raise the temperature of 1 kilogram of a material by 1 kelvin

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Specific Heat is measured in joules per kilogram-kelvin, or J/(kg.K)

Temperature, Thermal Energy, and Heat
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A material with a high specific heat can absorb a great deal of thermal energy without a great change in temperature.

Change in Energy =
Mass x Specific Heat x Change in Temperature

The Transfer of Heat
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What are the three forms of heat transfer? In what direction does heat move?

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How are conductors and insulators different?

The Transfer of Heat
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How is Heat Transferred? Heat is transferred by conduction, convection, and radiation.

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The Transfer of Heat
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Conduction: heat is transferred from one particle of matter to another without the movement of the matter.

The Transfer of Heat
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Convection: heat is transferred by the movement of currents within a liquid Convection Current: a current caused by the rising of heated fluid and sinking of cooled fluid

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The Transfer of Heat
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Radiation: the transfer of energy by electromagnetic waves

The Transfer of Heat
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Heat Moves One Way If two objects have different temperatures, heat will flow from the warmer object to the colder one.

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The Transfer of Heat
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Conductors and Insulators A conductor transfers thermal energy well. An insulator does not transfer thermal energy well.

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The Transfer of Heat
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Conductors: a material that conducts heat well Insulators: a material that does not conduct heat well

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Just Add Water
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Skills Lab, page 188, 189

Thermal Energy and States of Matter
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What are three states of matter? What causes matter to change state?

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What happens to a substance as its thermal energy increases?

Thermal Energy and States of Matter
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States of Matter Most matter on Earth can exist in three states—solid, liquid, and gas.

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Thermal Energy and States of Matter
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Solids Liquids

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Gases

Thermal Energy and States of Matter
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Change of State: the physical change from one state of matter to another Matter can change from one state to another when thermal energy is absorbed or released.

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Thermal Energy and States of Matter
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Solid-Liquid Changes of State Melting: the change of state from a solid to a liquid Freezing: the change of state from a liquid to a solid

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Thermal Energy and States of Matter
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Liquid—Gas Changes of State Evaporation: vaporization taking place at the surface of a liquid

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Boiling: vaporization taking place below the surface of a liquid
Condensation: a change from the gas state to the liquid state

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Thermal Energy and States of Matter
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Thermal Expansion: the expanding of matter when it is heated As the thermal energy of matter increases, its particles spread out and the substance expands.

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Uses of Heat
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How do heat engines use thermal energy? How do refrigerators keep things cold?

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What Happens at the Pump?
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Discover Activity, page 195

Uses of Heat
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Heat Engines: a device that transforms thermal energy to mechanical energy Heat engines transform thermal energy to mechanical energy.

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Uses of Heat
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External Combustion Engines: engines that burn fuel outside the engine in a boiler Internal Combustion Engines: engines that burn fuel in cylinders inside the engine

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Uses of Heat
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Cooling Systems Refrigerators

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

Uses of Heat
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Refrigerant: a substance that absorbs and releases heat in the refrigerator Air Conditioners

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Thermal Energy and Heat
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Review

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