“Gravitation is not responsible for people falling in love.” Albert Einstein

BellringerWhy does a gas take the shape and volume of its container? Why does a liquid take the shape but not the volume of its container?

SOLiDSHow are the structure and

properties of solids related?How are the structure and

properties of solids related?

ORDERLY ARRANGEMENT of particles

ORDERLY ARRANGEMENT of particles

FIXED LOCATIONS of particles

FIXED LOCATIONS of particles

Phase Differences

SolidSolid – definite volume and shape; particles packed in fixed positions; particles are not free to moveSolidSolid – definite volume and shape; particles packed in fixed positions; particles are not free to move

LiquidLiquid – definite volume but indefinite shape; particles close together but not in fixed positions; particles are free to moveLiquidLiquid – definite volume but indefinite shape; particles close together but not in fixed positions; particles are free to move

GasGas – neither definite volume nor definite shape; particles are at great distances from one another; particles are free to move

GasGas – neither definite volume nor definite shape; particles are at great distances from one another; particles are free to move

Crystalline Solids

highly regular arrangement of particleshighly regular arrangement of particles

Amorphous Solids

disorder in their

structures (glass and

plastic).

disorder in their

structures (glass and

plastic).

Think about it…

Why does a solid have a definite shape and a definite volume?

Water

• Water exists on our planet in three states.

• Ice, water, and water vapor

• What causes water to be in one phase or another?

ENERGY

• When energy is added to a substance that energy causes the particles in the substance to move faster and farther apart.

• What happens to the particles when energy is taken away from a substance?

Phase Change• Energy content is responsible for the

different phases of matter.

• Matter can be made to change phase when energy is added to or taken away from a substance.

ENDOTHERMIC: heat/ energy is ABSORBEDENDOTHERMIC: heat/ energy is ABSORBED

EXOTHERMIC: heat/energy is RELEASED

EXOTHERMIC: heat/energy is RELEASED

Block of Ice to Steam

• Block of Ice to Water Vapor

Things to consider: • What does the motion of the particles look like?• When are they changing phases?• What is the temperature when they change

phases? • Do all of them change phases at once?

Melting- Solid to Liquid

• the substance absorbs heat energy.

• Melting Point– Water 0° C.– Table salt 801° C.– Diamond 3700° C.

What happens to the particles?What happens

to the particles?

melting

Freezing- Liquid to Solid

• a substance loses heat energy.

• The freezing point of a substance is equal to the melting point!

What happens to the particles?What happens

to the particles?

Phase Change Graph

Freezing

melting

Vaporization- Liquid to Gas

• substance absorbs heat energy.

• Vaporization occurring at the surface of a liquid is called evaporation.

What happens to the particles?What happens

to the particles?

Evaporation- a Cooling Process

• As water in the perspiration evaporates from your skin it absorbs and carries away heat energy from your body.

Boiling

• When all the particles in the liquid have enough energy to vaporize, the liquid begins to boil

• The particles travel to the surface

Boiling Point

• Boiling Point – temperature at which a substance boils.– Water 100° C.– Table salt 1413° C.– Diamond 4200° C.

• What is the difference between evaporation and boiling?

Phase Change Diagram

Freezing

meltingvaporization

Condensation- Gas to Liquid

• A substance in the gas phase that loses heat.

What’s going on here?? Why do we have condensation on a cold glass?

Condensation

• Water vapor in surrounding air loses heat energy when it comes in contact with the cold glass. Water vapor condenses and becomes liquid drops of water.

Phase Change Graph

condensation Freezing

meltingvaporization

Sublimation – Solid to Gas

• surface particles of a solid change directly into a gas.

Sublimation

• http://www.youtube.com/watch?v=_jvicQ2Xj0o

Phase Change Graph

condensation Freezing

meltingvaporization

Sublimation

Deposition – gas to solid

• You may notice this in the cold winter with snow. The snow does not melt, but slowly disappears.

• Dry ice goes directly from solid carbon dioxide to gas.

condensation Freezing

meltingvaporization

Sublimation

Deposition

Energy in Phase Change

Phase Change

• Phase Change Diagram in Water

Temperature Comparisons

• Boiling Point of H2O

212 F100 C

• Melting Point of H2O

32 F0 C

• Freezing Point of H2O

32 F0 C

Phase Diagram

Triple Point: only set of conditions in which all three phases can exist at once