Solids, Liquids, and Gases: A First Look Teacher s Guide

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1 Teacher s Guide Grade Level: K-2 Curriculum Focus: Science Lesson Duration: Four class periods Program Description Solids, Liquids, and Gases: A First Look In this program students are encouraged to take a closer look at the world around them. In doing so they will discover that matter is everywhere. Students will learn about the three types of matter solids, liquids, and gases and will learn that all matter takes up space and has weight. (It is more accurate to say that matter has mass rather than weight. For this young audience, however, the term weight is used because it is a concept that they can more easily grasp. Technically weight depends on gravity, while mass is the amount of material in something. Weight can change with location; mass cannot.) Students will explore the unique characteristics of each type of matter and discover how matter changes from one form to another. The program presents activities that demonstrate some of the characteristics of matter; students may easily duplicate these activities in the classroom or at home. Discussion Questions What are the three types of matter? How is all matter alike? Why isn t a shadow or a whisper matter? How are solids different from liquids and gases? How are liquids like solids? How are liquids different from solids? What is evaporation? What is condensation? Give an example of each. What is freezing? What is melting? Give an example of each. Lesson Plan Student Objectives Learn that matter can be a solid, liquid, or gas. Understand that matter takes up space and has weight. Identify the characteristic properties of solids, liquids, and gases. Explain that solids have a shape of their own that is not easily changed. Explain that liquids have no definite shape but take the shape of the container into which they are put.

2 Teacher s Guide 2 Explain that gases have no definite shape. Compare and contrast the characteristic properties of solids, liquids, and gases. Identify and describe processes that can be used to change physical properties of materials. Understand the basic difference between physical and chemical changes in matter. Conduct simple experiments; observe and explain the results. Create an illustrated report on the three types of matter. Materials Solids, Liquids, and Gases: A First Look Computer with Internet access Two tall cylinders and a short beaker for holding water (all having the same capacity), as well as red and blue food coloring for the water (Procedure #3) Balloons, a straight stick, rubber bands or tape, string, and a push pin (Procedure #4) An empty milk carton (Procedure #6) Procedures 1. Prior to viewing the program introduce students to some of the key terms that will be used: solids, liquids, gases, and matter. Use classroom items and food or beverage items that students enjoy as examples of solids and liquids. Next have students take a deep breath, hold it a few seconds, and then exhale. Ask them what they were breathing in and holding. (Most will know this is air.) Explain that air is a mixture of gases that surrounds the earth. Tell students that they will be seeing a program about solids, liquids, and gases, all of which are different kinds of matter anything that takes up space and has weight. What differences do students notice between the three different types of matter? (Younger students may find concrete examples of solids and liquids helpful for making comparisons.) What similarities do students notice? 2. After viewing the program review the basic concepts, such as types of matter and processes by which matter is changed from one form to another. Clarify concepts and vocabulary as needed. 3. Re-creating Program Activities Comparing Volumes of Liquids in Different Containers: Show students two containers: a tall cylinder holding red water and a short beaker holding an equal amount of blue water. Ask students which contains the most liquid. Next empty the beaker of blue water into a tall cylinder like the one holding the red water, thus demonstrating that the beaker held an equal amount of water. The purpose of this activity is to demonstrate that volume is different from shape. The activity also introduces the idea that tools are used to measure the volume of liquids. 4. Re-creating Program Activities Balance Scale Using Balloons: Inflate two balloons as uniformly as possible. Attach them to either end of a straight stick using tape or rubber bands. Suspend the stick from a chair by a string tied to the center point of the stick. (The chair prevents the stick from swinging around but doesn t interfere with its operation as a scale.)

3 Teacher s Guide 3 Once you have balanced the balloons, use a pin to puncture one of the balloons near its knot. (This puncture point makes it less likely to pop.) Observe and discuss the results. The purpose of this activity is to demonstrate that air has weight. It also introduces the use of a balance scale as a means of measurement. Note: If students don t understand how a balance scale works, ask them to think of a seesaw. Ask them what happens when both people on the seesaw weigh about the same. Ask them what happens if one person is much heavier than the other. 5. Condensation: Ask students if they have ever noticed dew on grass early in the morning. Explain that dew forms when warm water vapor in the air meets the cold ground and condenses. Explain that fog is another example of water vapor condensing. Ask students if they have ever drawn a picture on a window that was misted up. Ask them these questions: How did the window get that way? What are some other examples of condensation? What process makes dew, fog, or the mist on the window disappear? Where does the water vapor go? 6. Water and Freezing: Explain to students that when most liquids freeze, the solids they form take up less space. Water is an exception. It expands when it freezes. Demonstration: To illustrate that water expands when it freezes, cut the top off a small, empty milk carton. Have students fill the carton to the top with water and put it in a freezer. When the water freezes the ice will bulge out of the top of the carton or perhaps even split the sides. Ask students to predict what would happen if the frozen water were allowed to melt. 7. Physical Versus Chemical Changes in Matter: The program discusses physical changes in matter that result from freezing, melting, evaporating, and condensing. Explain that a physical change causes matter to change form, but the change is reversible. For example, water that is frozen to form ice can be melted back into water again. Water and ice are two forms of the same thing. Discuss other things that may be changed physically by these processes (for example, butter, ice cream, candle wax, peanut butter, salt mixed with water, or cheese). The program also introduces chemical changes in matter by showing how the mixing of baking soda and vinegar produces a new substance, carbon dioxide. Explain to students that a chemical change results in the formation of one or more new substances and cannot be reversed. Help clarify the concept with the following questions: If you burn a piece of wood, does it change? Can you unburn it? When you mix eggs, sugar, butter, and flour together and bake the mixture, can you unbake it and return the ingredients to their original form? When you cook an egg, are you causing a physical change or a chemical change in the egg? 8. Mass and Weight: Because of the young age of the audience, the program uses the term weight rather than mass. Weight is a more familiar term for most young students. A more accurate definition of matter, however, would use the term mass. An object s mass is the amount of matter in it. The weight is the pull of gravity on an object. Its mass is not affected by its location, whereas its weight can be. (For example, place a 60-pound child on the moon, and the child will weigh only 9.9 pounds, but the mass of the child s body will stay the same.) The following Web site offers exercises that you may use or adapt to help older students understand this concept: Mass Versus Weight

4 Teacher s Guide 4 9. Have students use what they have learned to write a short, illustrated report on the three types of matter. For younger students this may consist primarily of labeled drawings. Older students should also provide a brief description of the characteristics of each type of matter. Assessment Use the following three-point rubric to evaluate students work during this lesson. Vocabulary 3 points: Students were attentive and highly engaged in class discussions; participated fully in program-related activities; produced a neat, well-done report that demonstrated clear understanding of the topic. 2 points: Students participated in class discussions; participated sufficiently in programrelated activities; produced a satisfactory report that demonstrated adequate understanding of the topic. 1 point: Students participated minimally in class discussions; participated minimally in program-related activities; produced an unsatisfactory report that demonstrated poor understanding of the topic. air Definition: Gases forming the atmosphere; the invisible mixture of gases that surrounds the earth Context: Air has no shape of its own, but it does take up space. breathe Definition: To inhale air into the lungs and exhale it from the lungs Context: We must breathe in order to stay alive. cloud Definition: A visible mass of water or ice particles in the atmosphere from which rain and other forms of precipitation fall Context: Clouds form when warm water vapor rises, hits cool air above, and condenses around tiny specks of dust. condensation Definition: Process of changing from a gas to a liquid Context: When warmer air comes into contact with a cold window, condensation will cause tiny drops of water to form on the surface. evaporation Definition: The process of changing from a liquid to a gas Context: On a hot day evaporation of moisture on our skin helps to keep our bodies cool.

5 Teacher s Guide 5 freezing Definition: The process of changing from a liquid to a solid by withdrawing heat Context: During cold winter months freezing can make the surface of a pond or lake hard enough to walk on. gas Definition: A substance such as air that is neither a solid nor a liquid at ordinary temperatures and that has the ability to expand indefinitely Context: Both a gas and a liquid have no shape of their own. liquid Definition: A state of matter in which a substance flows and takes the shape of the container into which it is put Context: Like a solid and a gas, a liquid can be weighed. mass Definition: The amount of material an object has in it Context: Mass is measured by using a balance scale and comparing a known amount of matter with an unknown amount of matter. matter Definition: Anything that takes up space and has mass Context: Matter can take the form of a solid, liquid, or gas. melting Definition: The process whereby heat changes something from a solid to a liquid Context: A piece of butter changes from a solid to a liquid by being melted in a pan over heat. solid Definition: A state of matter in which a substance has a definite shape and volume Context: The shape of a solid is not easily changed. volume Definition: The size of a three-dimensional space enclosed within or occupied by an object Context: The volume of a liquid remains the same even if its shape changes. water vapor Definition: Water in the form of a gas Context: The air around us is full of water vapor. weight Definition: The measurement of the pull of gravity on an object

6 Teacher s Guide 6 Context: The weight of an object on Earth is different from its weight on the moon. Academic Standards National Academy of Sciences The National Academy of Sciences provides guidelines for teaching science in grades K 12 to promote scientific literacy. To view the standards, visit this Web site: This lesson plan addresses the following national standards: Science as inquiry: Abilities necessary to do scientific inquiry; Understanding about scientific inquiry Physical science: Properties of objects and materials Earth and space science: Properties of earth materials Mid-continent Research for Education and Learning (McREL) McREL s Content Knowledge: A Compendium of Standards and Benchmarks for K 12 Education addresses 14 content areas. To view the standards and benchmarks, visit This lesson plan addresses the following national standards: Science Physical Sciences: Understands the structure and properties of matter Science Nature of Science: Understands the nature of scientific inquiry Life Skills Thinking and Reasoning: Effectively uses mental processes that are based on identifying similarities and differences Support Materials Develop custom worksheets, educational puzzles, online quizzes, and more with the free teaching tools offered on the DiscoverySchool.com Web site. Create and print support materials, or save them to a Custom Classroom account for future use. To learn more, visit Credit Patricia A. Peirson, freelance writer and former elementary school and adult ESL educator