3.1 Solids, Liquids, and Gases

Do you recognize the object in Figure 1? It is a carpenter's level. A level can be used to see whether a surface is perfectly horizontal. The level has one or more transparent tubes inside a metal or wooden frame. Inside each tube is a clear liquid, such as alcohol, and an air bubble. When a carpenter places the level on a surface that is perfectly horizontal, the air bubble stays in the middle of the horizontal tube. The bubble moves to the high end of the tube if the surface is slanted.

The metal, alcohol, and air in a carpenter's level represent three states of matter. At room temperature, most metals are solids, alcohol is a liquid, and air is a gas. In this chapter, you will learn why the appearance and behavior of solids, liquids, and gases are different.

Figure 1 Carpenters use a level to find out if a surface is perfectly horizontal. In the level shown, three clear plastic tubes are set into an aluminum frame. Each tube contains a liquid and a gas. Classifying What property could you use to distinguish the liquid or gas from the solids in a level?

A carpenter's level with a section zoomed in to show  a glass tube with a liquid and a bubble in its center.

Describing the States of Matter

If you were asked to classify some materials as solids, liquids, or gases, you would probably find the task fairly easy. But could you describe what method you used to classify the materials? You might notice that some materials have a definite shape and volume and some materials do not.Materials can be classified as solids, liquids, or gases based on whether their shapes and volumes are definite or variable. Shape and volume are clues to how the particles within a material are arranged.


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Table of Contents

Physical Science CHAPTER 1 Science Skills CHAPTER 2 Properties of Matter CHAPTER 3 States of Matter CHAPTER 4 Atomic Structure CHAPTER 5 The Periodic Table CHAPTER 6 Chemical Bonds CHAPTER 7 Chemical Reactions CHAPTER 8 Solutions, Acids, and Bases CHAPTER 9 Carbon Chemistry CHAPTER 10 Nuclear Chemistry CHAPTER 11 Motion CHAPTER 12 Forces and Motion CHAPTER 13 Forces in Fluids CHAPTER 14 Work, Power, and Machines CHAPTER 15 Energy CHAPTER 16 Thermal Energy and Heat CHAPTER 17 Mechanical Waves and Sound CHAPTER 18 The Electromagnetic Spectrum and Light CHAPTER 19 Optics CHAPTER 20 Electricity CHAPTER 21 Magnetism CHAPTER 22 Earth's Interior CHAPTER 23 Earth's Surface CHAPTER 24 Weather and Climate CHAPTER 25 The Solar System CHAPTER 26 Exploring the Universe Skills and Reference Handbook