Physical and Chemical Changes

Physical and Chemical Changes

PHYSICAL CHANGES

• Alters the appearance and physical properties like: size, shape, color, weight, density

• Changes phase: freezes, melts, evaporates, condenses

PHYSICAL CHANGES

• Chemical composition DOES NOT change

• There is NO chemical reaction

• Does NOT create a new substance

• Can sometimes be reversed

Multiple Select

Choose all of the examples of physical changes:

CHEMICAL CHANGES

• A chemical reaction happens

• A new substance with a different composition & different properties is formed

• Changes are irreversible

CHEMICAL CHANGES

• change in color, release an odor/gas

• releases or absorbs heat

• it burns

• changes color

• creates light

• forms a solid compound or precipitate

Multiple Select

Choose all of the examples of chemical changes:

Let's look at the differences...

• Chemical change is a result of a chemical reaction

• Physical change is when matter changes form but not chemical identity

More differences...

• Chemical changes affect chemical properties and physical properties and they are irreversible

• Physical changes affect only physical properties (shape, size, color, etc) and they are reversible

More differences...

• Chemical changes involve absorption or evolution of energy during a chemical reaction

• There is no absorption or evolution of energy in a physical change

Last difference (for now)

• A Chemical Change creates a new product/substance

• A Physical Change does not create a new product/substance

QUESTION TIME

READ THE STATEMENTS AND CHOOSE TRUE OR FALSE

Multiple Choice

Matter changes form in a physical change

• true

• false

Multiple Choice

The chemical identity is changed in a chemical change

• true

• false

Multiple Choice

Chemical changes affect only the chemical properties

• true

• false

Multiple Choice

Both chemical and physical changes can be reversed

• true

• false

Multiple Choice

Size, shape and color are examples of physical properties

• true

• false

Multiple Choice

During a chemical reaction energy is absorbed or transformed

• true

• false

Multiple Choice

Physical changes do not absorb or transform energy

• true

• false

Multiple Choice

Physical changes create new products

• true

• false

Let's take a look at more examples

Burning

Physical or chemical change?

Burning

CHEMICAL CHANGE

Rusting

Physical or chemical change?

Rusting

CHEMICAL CHANGE

Rotting (decomposing)

Phsyical or chemical change?

Rotting (decomposing)

CHEMICAL CHANGE

Melting

Physical or chemical change?

Melting

PHYSICAL CHANGE

Boiling

Phsyical or chemical change?

Boiling

PHYSICAL CHANGE

Freezing

Physical or chemical change?

Freezing

PHYSICAL CHANGE

Shred, tear, break, cut, crumble...

Physical or chemical change?

Shred, tear, break, cut, crumble...

PHYSICAL CHANGE

QUIZ TIME

How much do you know?

Multiple Choice

Which of the following is an example of a physical change?

• burning

• boiling

• rusting

Multiple Choice

Which of the following is an example of a chemical change?

• freezing

• breaking

• rotting

Multiple Choice

After you eat an apple, your stomach digests it. This is an example of...

• a chemical change

• a physical change

Multiple Choice

If you dissolve sugar in water, this is an example of...

• a chemical change

• a physical change

Multiple Choice

When you make a cake, you first must mix all of the ingredients together. This is an example of a ....

• chemical change

• physical change

Multiple Choice

When you put the cake into the oven to bake it, this is an example of a....

• chemical change

• physical change

Multiple Choice

How do we know if a chemical change has occurred?

• Heat or energy is released or absorbed

• the color changes

• the size is changes

Open Ended

Name 3 physical changes

Open Ended

Name 3 chemical changes