science hands-on Level Six PEGUIS Jennifer Lawson Joni Bowman Kevin Chambers Randy Cielen Nancy Josephson Anita Kamal PUBLISHERS

Transcription

1 hands-on science Level Six Jennifer Lawson Joni Bowman Kevin Chambers Randy Cielen Nancy Josephson Anita Kamal PEGUIS PUBLISHERS Winnipeg Manitoba Canada

2 Contents Introduction 1 Assessment 11 Unit 1: Diversity of Living Things 23 Books for Children 24 Web Sites 25 Introduction 26 1 Introduction to Classification 28 2 The Animal Kingdom 32 3 Comparing and Contrasting Animals 44 4 Investigating an Arthropod Colony 52 5 The Plant Kingdom 61 6 Adaptations 65 7 Fungus 72 8 Pond Study 76 9 Bacteria Fossils 92 References for Teachers 110 Unit 2: Flight 111 Books for Children 112 Web Sites 113 Introduction Adaptations of Living Things: Movement Through Fluids Properties of Fluids Lighter-Than-Air Flying Devices Bernoulli s Principle The Role of Lift in Overcoming Gravity Forces Affecting Flight Propulsion Using Unbalanced Forces to Steer Flying Devices Pneumatic Power Designing and Constructing Aircraft Comparing Aircraft and Spacecraft History of Flight 173 References for Teachers 175 Unit 3: Electricity 177 Books for Children 178 Web Sites 179 Introduction Static Electricity Current Electricity Electricity From Chemical Sources Electrical Circuits Electrical Conductors and Insulators Electrical Switches Parallel and Series Circuits With Multiple Batteries Parallel and Series Circuits With Multiple Light Bulbs Designing and Constructing an Electrical Device Constructing an Electromagnet Motors: Transforming Electricity into Motion Generators: Transforming Motion into Electricity Nonrenewable Sources of Energy Renewable Sources of Electrical Energy Consumption and Conservation of Electrical Energy 244 References for Teachers 254 Unit 4: The Solar System 255 Books for Children 256 Web Sites 257 Introduction The Solar System The Planets The Sun The Earth/Sun Relationship: The Day/Night Cycle The Earth/Sun Relationship: The Year Cycle Using the Sun to Tell Time 284

3 7 The Surface of the Moon Gravity: Mass and Weight Moon Phases Lunar Eclipse Space Exploration: A Trip to the Moon Canadian Contributors to Space Science Contributions of Space Exploration Advantages and Disadvantages of Space Exploration Constellations Astronomy Versus Astrology 325 References for Teachers 327

4 Introduction Program Introduction Hands-On Science develops students scientific literacy through active inquiry, problem solving, and decision making. With each activity in the program, students are encouraged to explore, investigate, and ask questions as a means of heightening their own curiosity about the world around them. Students solve problems through firsthand experiences, and by observing and examining objects within their environment. In order for students to develop scientific literacy, hands-on experience is of utmost importance in fact, it is essential. The Foundations of Scientific Literacy Hands-On Science focuses on the four foundation statements for scientific literacy in Canada, as established in the Pan-Canadian Protocol.* These foundation statements are the bases for the learning outcomes identified in Hands-On Science. Foundation 2: Skills Students will develop the skills required for scientific and technological inquiry, for solving problems, for communicating scientific ideas and results, for working collaboratively, and for making informed decisions. Foundation 3: Knowledge Students will construct knowledge and understandings of concepts in life science, physical science, and earth and space science, and apply these understandings to interpret, integrate, and extend their knowledge. Foundation 4: Attitudes Students will be encouraged to develop attitudes that support responsible acquisition and application of scientific and technological knowledge to the mutual benefit of self, society, and the environment. Foundation 1: Science, Technology, Society, and the Environment (STSE) Students will develop an understanding of the nature of science and technology, of the relationships between science and technology, and of the social and environmental contexts of science and technology. *Common Framework of Science Learning Outcomes K-12: Pan-Canadian Protocol for Collaboration on School Curriculum (1997). 1

5 3 Electricity From Chemical Sources Science Background Information for Teachers Chemical energy is a major source of electricity. Examples of chemical energy sources are wet and dry cells. A wet cell contains acidic liquid (diluted sulphuric acid) and electrodes of lead dioxide and spongy lead. Car batteries consist of several wet cells joined together. A dry cell contains acidic paste, zinc, and carbon electrodes (rods). Note: The cylindrical batteries used in flashlights, for example, are really single dry cells, not batteries in the true sense. A battery is made up of several cells joined together. How a Battery Works: When a battery is connected by wires to a device such as a light bulb, the acidic paste begins to act on the metal. The carbon rod becomes positively charged and the zinc becomes negatively charged. As a result, an electric current runs through the paste and into the wires outside the cell or battery. There are two types of batteries: 1. The one-time use battery, which generates an electrical current chemically. When the original chemicals have been changed in the process of using energy to move electrons, the battery is no longer useful. 2. Rechargeable batteries, in which the chemicals giving energy to electrons can be returned to their original state by running an electric current through them in the reverse direction. The battery is then ready for use again. A car battery is an example. There are some advantages to using batteries. Batteries are: compact portable adaptable for many different applications some types can also be recharged for further use There are disadvantages to using batteries: Batteries are: costly made of metals and chemicals that create pollution concerns difficult to dispose of. Toxic chemicals leak out from decaying batteries in landfill sites and may leak into ground water that is used for drinking made from nonrenewable resources the supply of materials they are produced from is limited Materials several 6 or 9 volt dry cell batteries several different single dry cells, such as AA and C cells diagram of a single dry cell (included) (Make an overhead transparency of this sheet.) (3.3.1) overhead projector plastic cups strips of copper and zinc (available from science supply companies) Note: Prior to beginning this activity, clean the zinc and copper strips with steel wool. insulated wire scissors paper clips L.E.D.s (light emitting diode. These can be purchased through science supply companies and electronics or hobby stores. Ensure that you obtain L.E.D.s with the lowest voltage so that they will light up when making the model of the battery. Conduct this experiment yourself before doing it with the class to ensure that the materials used allow students to meet with success. If these are unavailable, a galvanometer can be used to detect electric current.) Unit 3 Electricity 193

6 3 water vinegar Activity: Part One Note: Stress to students that batteries and single cells should never be disassembled. Divide the class into working groups. Provide each group with a 6 or 9 volt dry cell battery and two different single dry cells. Have the students examine, discuss, and compare the various batteries and cells, using activity sheet A to record their ideas. Following this investigation, ask: What are batteries? What are batteries used for? What electrical devices use batteries as a power source? How are these batteries different from one another? How are they the same? How do you think a battery works? What is inside a battery? Discuss the chemicals and metals inside batteries. Display the diagram of the single dry cell on the overhead. Use the Science Background Information for Teachers as a guide to discussing and explaining these ideas. Activity: Part Two In their groups, provide the students with the materials they will need to make a homemade wet cell. Have them use activity sheet B as a guide for this investigation. Following this activity, discuss results. Ask: What happened to the L.E.D. when water was poured into the glass? Why do you think the light did not come on? What happened to the L.E.D. when vinegar was added? Why do you think this happened? Explain that vinegar is an acid. When it is added to the water, a chemical reaction occurs with the metal strips. This chemical reaction causes electrons to flow from the zinc strip, through the wire, to the copper strip. This flow of electrons, or electrical current, causes the L.E.D. to light up. Activity Sheet A Directions to students: Draw a diagram of each cell or battery. Examine them carefully and describe each. Answer the questions at the bottom of the page (3.3.2). Activity Sheet B Directions to students: Use the sheet as a guide for constructing a model of a wet cell. Make sure you answer the questions (3.3.3). Extensions Use the wet cell model to test the acidity of a lemon. Insert the zinc and copper strips into a lemon, then connect the wire to the strips with paper clips. Touch the L.E.D. to the wire, or hook wires onto a galvanometer. This activity can also be done with a potato. Use a galvanometer to test the power of various sized dry cell batteries (6 and 9 volt) and single cells. Challenge the students to test different brands of batteries to find out which lasts longest. The batteries can be tested in flashlights, radios, battery-run toys, and so on. To control variables, be sure the students use identical items for testing batteries (such as three flashlights). 194 Hands-On Science Level 6

7 3 Invite an auto mechanic to the class to discuss how car batteries work. Discuss and record the advantages and disadvantages of using chemical energy as a source of electricity. Unit 3 Electricity 195

8 Single Dry Cell (flashlight battery) Peguis Publishers This page may be reproduced for classroom use

9 Date: Name: Batteries and Cells Diagram Description Peguis Publishers This page may be reproduced for classroom use. How are the battery and cells similar? How are they different?

10 Date: Name: Constructing a Model of a Wet Cell Peguis Publishers This page may be reproduced for classroom use. 1. Place the zinc strip and copper strip inside the plastic glass, on opposite sides. 2. Measure and cut two pieces of wire, each 15 cm long. 3. Cut about 3 cm of insulation off both ends of each wire. 4. Use a paper clip to attach the ends of the wire to the strips. 5. Fill the glass about 1/3 full with water. 6. Examine the L.E.D. (light emitting diode). This device will light up if an electric current flows through it. 7. Do you think the L.E.D. will light up if you touch the two wires to the prongs on the L.E.D.? 8. Test your predictions and record your observations. 9. Now add vinegar to the glass so that it is about 2/3 full. 10. Do you think the L.E.D. will light up now if you touch the two wires to the prongs on the L.E.D.? 11. Test your predictions and record your observations. 12. Why do you think the L.E.D. lit up? 13. How is this model like a store-bought battery?