Changes in Matter

Introduction

You hit a baseball out of the park and head for first base. You’re excited. The score is tied, and now your team has a chance of getting a winning home run. Then you hear a crash. Oh no! The baseball hit a window in a neighboring house. The glass has a big hole in it, surrounded by a web of cracks (see Figure below). The glass has changed. It’s been broken into jagged pieces. But the glass is still glass. Breaking the window is an example of a physical change in matter.

When glass breaks, its physical properties change. Instead of one solid sheet of glass, it now has holes and cracks.

Lesson Objectives

  • Define and give examples of physical changes in matter.
  • Define and give examples of chemical changes in matter.
  • State the law of conservation of mass.