Do Now November 8, 2012

1. Adding _______ causes the particles in a solid, liquid, or gas to move farther apart and faster. a)gravityb)heatc)massd)all of these

2. Which of the following correctly lists the states of matter from the most particle movement to the least particle movement? a)gas, liquid, solidb)solid, liquid, gasc)liquid, solid, gasd)gas, solid, liquid

3. Which of the following statements is true? a)Solid particles can vibrate, but gas and liquid particles cannot vibrate.b)Gas and liquid particles are always moving, but solid particles do not move.c)Molecules that compose matter only move when heat is added.d)Molecules that compose matter are in constant motion.

Phases of Matter:• Solid matter that has definite volume and shape. The molecules are packed together tightly and move slowly. • Liquid matter that has definite volume but not shape. Since the molecules of a liquid are loosely packed and move

with greater speed, a liquid can flow and spread. • Gas matter that has no definite volume or shape. Molecules of a gas are so loosely arranged and move so

rapidly that they will fill their container.

Phase Change Descriptions:• Melting

the change from solid to liquid. • Freezing

the change from liquid to solid. • Vaporization

the change from liquid to gas. • Evaporation

vaporization from the surface of a liquid. • Boiling

vaporization from within as well as from the surface of a liquid. • Condensation

the change from gas to liquid. • Sublimation

the change from solid to gas. • Deposition

the change from gas to solid.

Phase Change Diagram

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.

Block of Ice to Steam

• Block of Ice to Water Vapor

Melting- Solid to Liquid

• Melting is the changing of a solid to a liquid when the substance absorbs heat energy.• Melting Point• Water 0° C.• Table salt 801° C.• Diamond 3700° C.

Freezing- Liquid to Solid

• Opposite of melting: liquid changing to a solid is freezing.• Freezing occurs when a

substance loses heat energy.• The freezing point of a

substance is equal to the melting point!

Phase Change Graph

Vaporization- Liquid to Gas

• Vaporization is the changing of a liquid to a gas when the substance absorbs heat energy.• Vaporization occurring

at the surface of a liquid is called evaporation.

Evaporation- a Cooling Process

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

Boiling

• If enough heat energy is applied to a substance particles inside the liquid can change to gas.• These particles travel to

the surface of the liquid and then into the air. This process is called boiling.

Phase Change Graph

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?

Water Phase Change Graph

Condensation- Gas to Liquid

• Gases can change phase, also in a gas to liquid phase change.• A substance in the gas

phase that loses heat will change to a liquid. This is called condensation.

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

Sublimation – Solid to Gas

• Solid to gas phase change occurs when the surface particles of a solid change directly into a gas.

Sublimation – Solid to Gas

• 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.

Energy in Phase Change

Phase Change• Phase Change Diagram in Water

Temperature Comparisons

• Boiling Point of H2O212 F100 C

• Melting Point of H2O32 F0 C

• Freezing Point of H2O32 F0 C

Add the correct terms to the diagram…

Phase Change Graph

•Exit Activity

Fill in the phase changes in the blank provided.