1. Physical and Chemical Changes

2. Physical and Chemical Changes

3. What is a Physical Change?
A physical change is a change in matter where NO new materials form.
For example, if you cut a sheet of paper into pieces, you have changed physical properties of the paper including size and shape, but it is still paper. No new materials were formed.

4. What is a Physical Change?
Causing a physical change in a material changes one or more of its physical properties.
Most physical changes can be reversed (undone).
Changes in state are also physical changes. For example, water changing from solid to a liquid or gas is a physical change.

5. What is a Physical Change?
A mixture is matter made up of two or more materials. You combine the materials, but no new materials form. This is a physical change.

6. What is a Chemical Change?
A chemical change is a change in which one or more new types of matter form.
In a chemical change, materials react with one another. They combine in new ways to form other materials.

7. What is a Chemical Change?
Remember that cutting paper is a physical change. Burning paper would be a chemical change because new materials are formed.
The ability of a material to react with other materials a certain way is called a chemical property. Flammability is an example of a chemical property.

8. Examples of Chemical Changes/Properties
Burning – when a material burns, heat and light are given off
Wood, coal, gasoline, paper, and natural gas are all materials that can burn.
Rusting – Iron can rust when exposed to moisture

9. Examples of Chemical Changes

10. Signs of Chemical Changes
If new materials form, a chemical change has taken place.
Other signs a chemical change has taken place include:
Color change (fruit ripening, egg cooking)
Gases given off (baking soda and vinegar)
Temperature change without heating or cooling
Smells given off

11. Is it Physical or Chemical?
Ask yourself if the change can be easily reversed. Chemical changes are very hard if not impossible to reverse.

12. Physical and Chemical Changes Review