Lesson 3.3 Changes in Matter

3.1. Chapter 3: Introduction to Matter www.ck12.org

3.1 Chapter 3: Introduction to Matter

Chapter Overview

Matter is anything that has mass and volume. Matter has both physical and chemical properties. Elements are pure substances with unique properties. Compounds are unique substances that form when two or more elements combine chemically. Physical changes in matter are changes in physical properties. Chemical changes in matter are changes in chemical properties. Matter cannot be created or destroyed, even when it changes.

Online Resources

See the following Web sites for appropriate laboratory activities:

At the following URL, the first part of the lab is a good choice for Lesson 3.1; add the graphing part for enrichment.

• http://www.kwanga.net/chemnotes/density-lab.pdf

For Lesson 3.2, students can do the lab “Messing with Mixtures.” Worksheets and background notes are provided at these URLs:

• http://sciencespot.net/Media/messingmixtures.pdf

• http://sciencespot.net/Media/messingmixturesnotes.pdf

This teacher-developed lab hones students’ observational skills and really reinforces the differences between physical and chemical changes.

• http://people.wku.edu/bruce.kessler/IKE/Sciencematerials/PandCCLab.pdf These Web sites may also be helpful:

For Lesson 3.1, teach mass and volume with the mass and volume PowerPoint presentations and worksheets at this URL:http://sciencespot.net/Pages/classmetric.html .

Students can delve more deeply into elements in Lesson 3.2 with the activity at the following URL:http://www.p bs.org/wgbh/nova/teachers/activities/3114_origins.html .

When you teach Lesson 3.3, students can explore physical and chemical changes in matter with this excellent animation:http://www.wisc-online.com/objects/ViewObject.aspx?ID=SCE204 .

Pacing the Lessons

T

ABLE

3.1:

Pacing the Lessons

Lesson Class Period(s) (60 min)

3.1 Properties of Matter 1.5

3.2 Types of Matter 2.5

3.3 Changes in Matter 2.0

3.2. Lesson 3.1 Properties of Matter www.ck12.org

3.2 Lesson 3.1 Properties of Matter

Key Concept

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.

Standards

• 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

• MCR.6-8.SCI.10.1

• NSES.5-8.B.1.1

• AAAS.6-8.4.D.11, 15, 16; AAAS.6-8.4.G.1; AAAS.6-8.9.C.6

Lesson Objectives

• Define matter, mass, and volume.

• Identify physical properties of matter.

• List examples of chemical properties of matter.

Lesson Vocabulary

• 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(D=M/V)

• 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

Teaching Strategies

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.

Activity

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.

Differentiated Instruction

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.

Enrichment

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.)

Science Inquiry

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.

• http://www.inquiryinaction.org/pdf/InquiryinAction.pdf

3.2. Lesson 3.1 Properties of Matter www.ck12.org Common Misconceptions

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

Lesson Worksheets

Copy and distribute the lesson worksheets in theCK-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.

Lesson Quiz

Check students’ mastery of the lesson with Lesson 3.1 Quiz inCK–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?

3.3 Lesson 3.2 Types of Matter

Key Concept

Elements are pure substances with unique properties. The smallest particles of elements are atoms. Compounds are unique substances that form when two or more elements combine chemically. The smallest particles of compounds are molecules, but some compounds form crystals instead.

Standards

• SCI.CA.8.PS.3.b, c

• MCR.6-8.SCI.8.1, 2, 4, 7, 8

• NSES.5-8.B.1.1, 2, 3

• AAAS.6-8.1.A.4; AAAS.6-8.1.C.1; AAAS.6-8.4.D.1, 2, 3, 8, 17, 19; AAAS.6-8.10.F.1, 2

Lesson Objectives

• Describe elements and atoms.

• Describe compounds, molecules, and crystals.

• Define mixture, and identify types of mixtures.

Lesson Vocabulary

• atom: smallest particle of an element that still has the element’s properties

• colloid: homogeneous mixture in which the particles are large enough to reflect light and be seen but too small to settle or filter out of the mixture

• compound: unique substance that forms when two or more elements combine chemically

• crystal: rigid, lattice-like framework of many atoms bonded together that is formed by some compounds such as table salt

• element: pure substance that cannot be separated into any other substances

• mixture: combination of two or more substances in any proportions

• molecule: smallest particle of a compound that still has the compound’s properties

• solution: homogeneous mixture in which particles are too small to reflect light and be seen and also too small to settle or be filtered out of the mixture

• suspension: heterogeneous mixture in which particles are large enough to reflect light and be seen and also large enough to settle or be filtered out of the mixture

3.3. Lesson 3.2 Types of Matter www.ck12.org

Teaching Strategies

Introducing the Lesson

Students are likely to have learned about elements and atoms in previous science classes. Call on volunteers to share what they can recall about them. Tell the class they will learn about elements, atoms, and other types of matter in this lesson.

Demonstration

Reinforce the important idea that a compound is a unique substance that always has the same composition. Show students samples of two compounds that each contains only hydrogen and oxygen: water (H2O) and hydrogen peroxide (H2O2). Explain how the proportions of hydrogen and water differ in the two compounds. Also discuss how their properties differ (e.g., hydrogen peroxide is so reactive that it kills germs and bleaches color from hair).

Differentiated Instruction

Work with any students who need extra help to make a concept map of types of matter. A sample concept map is shown below:

Enrichment

Encourage a few creative students to make three-dimensional models of a crystal of sodium chloride. For example, they might use Styrofoam balls of different colors to represent the sodium and chloride ions and “bond” them together with glue or toothpicks. Invite students to explain their models to the rest of the class. Afterward, put the models on display in the classroom.

Science Inquiry

Have groups of students devise procedures for separating the following mixtures into their components based on their different physical properties:

• pepper and iron filings

• sugar and sand

Give groups a chance to share their procedures and offer each other feedback. You can have groups carry out the procedures if time allows.

Common Misconceptions

A common student misconception is that atoms are “mini-versions” of the elements they represent. For example, students might think that atoms of copper are copper-colored and the atoms of gold are gold-colored. Correct this misconception by explaining that atoms consist of smaller particles—called protons, neutrons, and electrons—that are identical in all atoms, regardless of the element. Atoms of different elements have different numbers of these particles and this is what gives the atoms different properties.

Reinforce and Review

Lesson Worksheets

Copy and distribute the lesson worksheets in theCK-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.

Lesson Quiz

Check students’ mastery of the lesson with Lesson 3.2 Quiz inCK-12 Physical Science for Middle School Quizzes and Tests.

Points to Consider

The properties of matter are not fixed. In fact, matter is always changing.

• What are some ways you have seen matter change?

• What do you think caused the changes?

3.4. Lesson 3.3 Changes in Matter www.ck12.org

3.4 Lesson 3.3 Changes in Matter

Key Concept

Physical changes are changes in the physical properties of matter. Chemical changes are changes in the chemical properties of matter. Matter cannot be created or destroyed even when it changes. This is the law of conservation of mass.

Standards

• SCI.CA.8.PS.5.d

• MCR.6-8.SCI.8.6, 8; MCR.6-8.SCI.12.7

• NSES.5-8.A.1.4; NSES.5-8.B.1.2

• AAAS.6-8.4.D.12, 17

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.

Lesson Vocabulary

• chemical change: change in matter that occurs when matter changes chemically into an entirely different substance with different chemical properties

• law of conservation of mass: law stating that matter cannot be created or destroyed

• physical change: change in one or more of matter’s physical properties

Teaching Strategies

Introducing the Lesson

Show students a small wooden toy and ask them to brainstorm ways they could change it (e.g., use a hammer to pound dents in it, cut it into smaller pieces with a saw, burn it in a fire, paint it to change its color, drill holes in it).

Tell students they will learn about changes in matter in this lesson.

Demonstration

Demonstrate physical and chemical changes by cutting a sheet of paper and burning an identical sheet of paper.

Discuss the products of each change and whether either change is reversible.

Differentiated Instruction

Guide students in making Frayer models for the terms physical change and chemical change. You can see a sample Frayer model below. Students should keep their completed models in their science notebook.

T

ABLE

3.2:

Sample Frayer model Term: physical change Definition: change in one or

more of matter’s physical properties.

Drawing: [Student sketch of a saw cutting a log]

Example:Cutting a log Non-example: Burning a log

Reinforce and Review

Lesson Worksheets

Copy and distribute the lesson worksheets in theCK-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.

Lesson Quiz

Check students’ mastery of the lesson with Lesson 3.3 Quiz inCK-12 Physical Science for Middle School Quizzes and Tests.

Points to Consider

Some physical changes in matter are changes of state.

• What are the states of matter?

• What might cause matter to change state?

www.ck12.org

C ^HAPTER

4 TE States of Matter

Chapter Outline

4.1 CHAPTER4: STATES OF MATTER