Matter is anything that has mass and volume. Mass is the amount of matter in a substance. Volume is the amount of space matter takes up. Matter has both physical and chemical properties. Physical properties can be measured or observed without matter changing to a different substance. Chemical properties of matter can be measured or observed only when matter undergoes a chemical change to become a different substance.
- SCI.CA.8.IE.9.f; SCI.CA.8.PS.6.a; SCI.CA.8.PS.7.c; SCI.CA.8.PS.8.a, b
- AAAS.6-8.4.D.11, 15, 16; AAAS.6-8.4.G.1; AAAS.6-8.9.C.6
- Define matter, mass, and volume.
- Identify physical properties of matter.
- List examples of chemical properties of matter.
chemical property: property of matter that can be measured or observed only when matter changes form and becomes something else
density: amount of mass in a given volume of matter
flammability: ability of matter to burn
mass: amount of matter in a substance or object
matter: anything that has mass and volume
physical property: property of matter that can be measured or observed without matter changing to a different kind of matter
reactivity: ability of matter to combine chemically with other substances
volume: amount of space that matter takes up
weight: amount of space that matter takes up
Introducing The Lesson
Introduce matter by asking the class to brainstorm examples of matter in the classroom. Students are likely to name visible objects such as books, desks, and other students. If they don’t mention air, tell them that most of the matter, by volume, in the classroom is invisible, and ask them to guess what it is. Conclude by saying that they will learn about matter and its properties in this lesson.
Put a variety of different small objects in a brown paper bag. For example, you might include a cotton ball, toothpick, pen, shoelace, lemon, orange, eraser, playing card, dry pasta, and paper clip. Include at least two objects, such as a lemon and an orange, that are difficult to distinguish by touch alone. Carry the bag around the classroom, and ask several different students to try to identify the objects by just reaching into the bag and feeling them. Use the activity to launch a discussion of physical properties of matter.
Question: What physical properties of matter did you use to identify the objects in the bag?
Answer: Students might mention properties such as hardness, texture, shape, and size.
For any objects students could not identify, show them the objects and ask them what other physical properties (observable with other senses) would have helped them identify the objects. Students might mention color, odor, or taste.
If you haven’t started a physical science word wall yet, this is a good time to start one because this lesson introduces basic concepts that are relevant to several other FlexBook® chapters, including matter, density, and physical and chemical properties. Pair any students who need extra help with students who excel, and assign each pair a lesson vocabulary term to add to the word wall. They should include the definition and an example of the assigned term. Encourage them to include a drawing as well.
Ask a few students to demonstrate differences in chemical reactivity. In their demonstration, have students mix vinegar with baking soda and with another, similar-looking substances such as salt that will not react with vinegar. Have them point out the evidence that the baking soda—but not the other substance—reacts with the vinegar. (Only the baking soda froths up when combined with vinegar. This happens because a chemical change has occurred and formed a new substance—carbon dioxide gas.)
Use one or more of the inquiry activities at the URL below to introduce physical properties that can be used to identify different liquids. The activities begin on page 131 of the PDF document, which is a product of the American Chemical Society’s Education Division. The comprehensive document provides a panoply of teaching resources, including background information, procedures, expected results, worksheets, and assessment rubrics.
Students commonly think that gases such as air are not matter because they are invisible. Demonstrate that gases consist of matter and take up space. Blow up a balloon and relate the increase in size of the balloon to the air that has been added to it. Explain that particles of air are constantly moving and bumping against the inner surface of the balloon, causing it to inflate.
Reinforce and Review
Copy and distribute the lesson worksheets in the CK-12 Physical Science for Middle School Workbook. Ask students to complete the worksheets alone or in pairs to reinforce lesson content.
Lesson Review Questions
Have students answer the Review Questions listed at the end of the lesson in the FlexBook® student edition.
Check students’ mastery of the lesson with Lesson 3.1 Quiz in CK–12 Physical Science Quizzes and Tests.
Points to Consider
The physical and chemical properties of substances can be used to identify them. That’s because different kinds of matter have different properties.
- What property could you use to tell the difference between iron and aluminum?
- How could you tell whether a liquid is honey or vinegar?