READ: Physical and Chemical Changes

Summary

• A physical change in matter is a change in one or more of matter’s physical properties. In a physical change, matter may change its size, shape, or state, but its chemical properties do not change.

• Because the chemical properties of matter remain the same in a physical change, a physical change is often easy to reverse.

• A chemical change occurs whenever matter changes into an entirely different substance with different chemical properties. Burning is an example of a chemical change.
• Signs of chemical change include the release of bubbles, a change of color, production of an odor, release of heat and light, and production of loud sounds.
• Because chemical changes result in different substances, they often cannot be undone. Some chemical changes can be reversed, but only by other chemical changes.

Vocabulary

• physical change: Change in one or more of matter’s physical properties.

• chemical change: Change in matter that occurs when matter changes chemically into an entirely different substance with different chemical properties.

CK-12 Foundation, Physical Science. http://creativecommons.org/licenses/by-nc-sa/3.0/