Physical and

Chemical

CHANGES

Physical changes are all about

energy and

states of matter

• In a physical change there is only a change of state—thermal energy is added or removed.

• The new substance has the same chemical properties as the old one.

• No new substance(s) are produced. • Physical changes can be reversed.

SOLIDS

_LIQUIDS_

GASES_

PLASMA

+ energy

+ energy

+ energy -energy

- energy

- energy

The Staircase of Phase Change

Subtracting energy slows molecule motion, causing matter to go back down the stairs to a lower energy level.

Adding energy speeds up molecule motion, causing matter to move up a

level on the stairs.

Chemical changes happen on a

molecular level.

•Plus, you cannot get the original materials back easily.

•In a chemical change one or more NEW substances are created.

•The new substance is different from the original.

•It has properties that are different than those of the starting materials.

Identify the following events as:

Physical Change

Ask yourself:1. Is the material still the

same basic material?2. Is it just a change of

state or phase?3. Is it really new or

different material?4. Can it be easily

reversed?

Chemical Change

Ask yourself:1. Are there any new or

different substances?2. Is the material different

from the original?3. Are the chemical properties

different?4. Can it be easily reversed?

glass breaking

hammering wood together to build a playhouse

melting butter for popcorn

separating sand from gravel

spoiling food

mixing Kool-Aid powder into water

bleaching your hair

fireworks exploding

squeezing oranges to make orange juice

frying an egg

pouring milk on your cereal

burning leaves

making salt water to gargle with

cream being whipped

burning toast

freezing chocolate covered bananas

melting Popsicles

cooking spaghetti

Glow Sticks

Cooking applesauce

Whipping cream

Adding milk to cereal

Burning leaves

Making frozen chocolate bananas

Hammering wood together

Bleaching your hair

Dissolving Kool-Aid in water

Spoiled food

Melting a popsicle

Breaking a glass

Exploding fireworks

Fourth of July Ashland, KY

Melting butter for popcorn

Cooking an egg

Separating sand and gravel

Burned toast

Squeezing oranges for juice

Quiz Time!

1. In a physical change there is only a change of state—_______ is added or removed.

2. The new substance has the same _________ properties as the old one.

3. No _____ substance(s) are produced.

4. Physical changes are easily ________.

Use these to complete the questions:Chemical Energy New Reversed

1. In a chemical change one or more _____ substances are created.

2. The new substance is different from the _________ substance.

3. It has properties that are _______ than those of the starting materials.

4. You _______get the original materials back easily.

Use these to complete the statements:Cannot Different New Original

The END