Students learn about solids, liquids, and gases in this interactive slide show. Animated cartoon characters explain concepts having to do with properties of matter. A self-checking quiz follows the lesson.

Help solve the mystery and find the missing crystal. Following the activity, read more about chemical and physical changes, and then take a quick quiz to check for understanding.

[Free Registration/Login may be required to access all resource tools.] Definition of physical change and examples, and how physical changes can be reversed.