Physical Change

Physical change is a change that occurs that does not change the identity of the substance A change in which matter looks different but is still the same matter . A change that affects the size, shape or color of a substance but does not affect its composition

EXAMPLES OF PHYSICAL CHANGES

• Cutting paper• Mashing potatoes• Painting a wall• Breaking glass• Melting marshmallows• Molding clay• Water freezing• Water boiling• Thawing meat

A physical change alters the form of a substance, but does not change it to another substance.

Making Orange Juice

Chemical change is a change that occurs causing the identity of the substance to change. Examples include:

>Burning wood>Digesting food>Potassium reacting with water

A chemical change can also be called a chemical reaction.

Wood burning to ash and smoke (a

new substance is formed)

Iron rusting

Marshmallows burning

Apple rotting

Toasting bread

Examples of Chemical Changes

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Example:

Baking a Cake

Indicators of a Chemical Change

Indicators of a chemical change can include:

Light is produced

Heat is either absorbed or produced

Gas is produced

There is a change in color

Formation of a precipitate

Differences between physical and chemical changes

With a physical change, the item can be change back to its original form

With a chemical change, the item cannot be changed back to its original form

IS IT A CHEMICAL OR A PHYSICAL CHANGE

Type of Change Physical Chemical

Melting ice

Burning wood

Souring milk

Wadding up paper

Rusting metal

Corn Starch and Water

Corn Plastic

Adapted from: www.dpi.state.nc.us/docs/curriculum/science/units/.../8unit2pt2.ppt

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