2008 phase changes

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Phase Changes

November 10, 2009

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Objectives

1. Describe each of the five phase changes

2. Define melting, freezing, vaporization, condensation, sublimation

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What is a physical change?

• Physical changes involve the changing of physical properties such as color, shape, phase, texture, hardness, odor

• Type of matter remains the same

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• Let’s take a closer look with water.

When water is frozen it is ice, a

solid. (0°C)

When ice is melting, it is heating up. Melted

ice is a liquid.

Once the ice has melted you have

liquid water. (1-99°C)

If you heat the water more it becomes

steam, a gas. (0°C)

TEMPERATURELOW HIGH

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Phase changes

• melting • freezing• vaporization• condensation• sublimation

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Melting

• Phase change from a solid to a liquid

• The temperature in which this occurs is the melting point

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Freezing

• Phase change of a liquid to a solid

• The temperature in which this occurs is the freezing point

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Vaporization

Phase change from a liquid to a gas

1. Evaporation - particles vaporize from the top

2. Boiling - particles vaporize throughout; occurs at boiling point

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Condensation

• phase change from a gas to a liquid

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Sublimation

• Sublimation is a phase change from solid to a gas

• Dry ice and iodine are examples solids that undergo sublimation

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• Physical changes between the states of matter can be produced by heating and cooling.

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http://www.explorelearning.com/index.cfm?method=cResource.dspDetail&ResourceID=30

Description of Phase Change

Term for Phase Change

Heat Movement During Phase Change

Solid to liquid MeltingHeat goes into the solid as it melts.

Liquid to solid FreezingHeat leaves the liquid as it freezes.

Liquid to gasVaporization, which includes boiling and evaporation

Heat goes into the liquid as it vaporizes.

Gas to liquid CondensationHeat leaves the gas as it condenses.

Solid to gas SublimationHeat goes into the solid as it sublimates.

Description of Phase Change

Term for Phase Change

Heat Movement During Phase Change

Solid to liquid MeltingHeat goes into the solid as it melts.

Liquid to solid FreezingHeat leaves the liquid as it freezes.

Liquid to gasVaporization, which includes boiling and evaporation

Heat goes into the liquid as it vaporizes.

Gas to liquid CondensationHeat leaves the gas as it condenses.

Solid to gas SublimationHeat goes into the solid as it sublimates.