Phases, Phase Changes, Chemical and Physical Changes By: Brianna Shields March 19, 2007.

Phases, Phase Changes,

Chemical and Physical Changes

By:

Brianna Shields

March 19, 2007

DO NOW• 1. What tool is used to measure mass?

• 2. What is one unit used to label density?

• 3. What is volume?

GOAL• To discuss the states of matter and the

terms relative to changes in state• To distinguish between chemical and

physical changes

QuickTime™ and aSorenson Video 3 decompressorare needed to see this picture.

Phases of Matter• Solid • 1. Has a definite shape

• 2. Has a definite volume

Phases of Matter• Solid • 3. Particles are tightly

packed (can’t move or flow well)

• 4. Low energy

Phases of Matter• Solid • 5. May be crystals with

repeating patterns– Ex: salt

Phases of Matter• Solid • 6. Amorphous solids

lose shape/flow like slow moving liquids– Ex: candle wax, window

glass, tar

Phases of Matter• Liquid • 1. No definite shape-

takes the shape of the container

• 2. Has a definite volume

Phases of Matter• Solid • 3. Particles are packed

loosely and flow slowly• 4. Average energy

Phases of Matter• Liquid • 5. Varying viscosities=

resistance of a liquid to flow– Honey has a high viscosity

Phases of Matter• Gas • 1. No definite shape-

takes shape of container• 2. No definite volume

Phases of Matter• Gas • 3. Particles are spread

far apart- fill all spaces• 4. Contantly moving and

bumping into eachother• 5. High energy

Phases of Matter• Gas • 6. Particles can be

squeezed in closer– Bumping into eachother and

walls causes pressure

Phase Website• Phases of matter at the molecular level

Phase Summary Chart• Work with a partner to fill in the phase

summary chart

Phase Changes• Phase

Changes• Matter such as water can

change from phase to phase by adding or taking away heat energy

Phase Changes• Melting • Solid to liquid

• Must take in heat energy• M.P of water = 0 C or 32 F

Examples of Melting

Phase Changes• Freezing • Liquid to solid

• Must lose heat energy• F.P of water = 0 C or 32 F

Examples of Freezing

Phase Changes• Evaporati

on• Liquid to gas• Must gain heat energy• B.P of water = 100 C or

212 F

Examples of Evaporation

Phase Changes• Condensatio

n• Gas to liquid• Must lose heat energy

Examples of Condensation

Phase Changes• Sublimati

on• Solid skips to gas• Must gain a lot of heat

energy• Ex:

– Freezer Frost– Dry Ice– Cirrus Clouds

Phase Change Website• Click here to view a phase change

Phase Change Diagram

Assessment• Determine what phase change is the

opposite of evaporation. Explain

Assessment• What type of phase change is seen in

this picture? Explain what occurs during this phase change

Assessment• What type of phase change is seen in

this picture? Explain what occurs during this phase change

Assessment• What phase change is the opposite of

freezing? Explain

Physical and Chemical Changes• Physical

Change• Change in the

appearance of a substance without changing its identity

• The atoms remain unchanged

Physical and Chemical Changes• Chemical

Change• A substance changes into

a new and different substance

• The atoms are altered• Often involves chemical

rx

Assessment: Physical or Chemical Change????