Developed in Consultation with Illinois Educators

Transcription

1 Developed in Consultation with Illinois Educators

2 Table of Contents Assessment Objectives Chapter 1 Practices of Science Lesson 1 Scientific Inquiry Lesson 2 Scientific Tools and Measurement , , Lesson 3 Safety in the Science Lab Chapter 1 Review Chapter 2 Structure and Function in Living Things Lesson 4 Levels of Organization in Living Things , Lesson 5 Animal and Plant Cells , , Lesson 6 Cell Division and Reproduction , , , , , Lesson 7 Heredity , , Lesson 8 Plant Structures and Functions , , Lesson 9 Reproduction in Flowering Plants , , , Lesson 10 Photosynthesis and Cellular Respiration Lesson 11 Classifying and Identifying Organisms , Chapter 2 Review Chapter 3 Living Things in Their Environments Lesson 12 Ecosystems , , Lesson 13 Competition and Limiting Factors in Ecosystems , Lesson 14 Food Webs Lesson 15 Cycles in Ecosystems Lesson 16 Biomes Lesson 17 Adaptations, Variations, and Natural Selection , , , , Lesson 18 The Fossil Record , Chapter 3 Review Chapter 4 Matter Lesson 19 Atoms, Elements, and Compounds , , , , , Lesson 20 The Periodic Table , , ,

3 Assessment Objectives Lesson 21 States of Matter and Changes of State , , , Lesson 22 Physical and Chemical Changes , , , , Lesson 23 Chemical Reactions and the Conservation of Matter , , Lesson 24 Acids and Bases , Chapter 4 Review Chapter 5 Energy Lesson 25 Forms and Transformations of Energy , Lesson 26 The Transfer of Heat , , , Lesson 27 Conductors, Insulators, and Electrical Circuits Lesson 28 Properties of Light , , , , Lesson 29 The Behavior of Light , , , , Chapter 5 Review Chapter 6 Force and Motion Lesson 30 Speed, Velocity, and Acceleration , Lesson 31 Newton s Laws of Motion Lesson 32 Gravitational Force and Buoyant Force , , , , Lesson 33 Work and Simple Machines Chapter 6 Review Chapter 7 Earth s Structure and Processes Lesson 34 Earth s Layers Lesson 35 The Theory of Plate Tectonics , , Lesson 36 Plate Motion and Earth s Changing Surface , Lesson 37 Weathering, Erosion, and Deposition , , Lesson 38 The Rock Cycle , Lesson 39 Soil Lesson 40 Earth s Atmosphere Lesson 41 Earth s Water , , , ,

4 Assessment Objectives Lesson 42 Weather Patterns , , Lesson 43 Climate , , Chapter 7 Review Chapter 8 Earth s History Lesson 44 Evidence of Earth s History , , Lesson 45 The Geologic Time Scale Lesson 46 The Effects of Plate Movements, Catastrophes, and Climate Change , , Chapter 8 Review Chapter 9 Astronomy Lesson 47 Days, Years, and Seasons , , Lesson 48 The Phases of the Moon and Tides , , , , Lesson 49 Eclipses Lesson 50 The Solar System , , , , , , Lesson 51 Stars, Galaxies, and Distances in Space , Chapter 9 Review Chapter 10 Science, Technology, and Society Lesson 52 Technological Design , , , Lesson 53 Technology and Society , , , Lesson 54 Using Science and Technology in the Workplace Lesson 55 Conserving Resources , Chapter 10 Review Investigations Investigation 1 Testing Conservation of Mass , , , , , , , , Investigation 2 Testing Soil Permeability , , , , , Glossary Pretest Posttest , , , , Table of Contents

5 Chapter 1 Lesson 1 Scientific Inquiry Objective: Key Words scientific inquiry scientific question hypothesis procedure experiment field study model data analyze conclusion Getting the Idea The goal of science is to gain knowledge that can be used to understand and explain the natural world. Scientists begin this work by asking questions. Scientists then seek answers to their questions by conducting scientific investigations. Scientific Questions The process by which scientists ask and seek answers to their questions about the natural world is called scientific inquiry. It is through scientific inquiry that scientists learn about natural processes and systems. The work of a scientist begins with a question. You probably ask many questions each day. Perhaps you asked your teacher a question about a homework assignment. You might have asked a parent if you could go to a movie. These types of questions cannot be answered by science. A scientific question is precise, or stated exactly, and can be answered through observation, measurement, testing, or analysis of research. For example, the question How big is an apple? is not a good scientific question. The term big is not precise; it may mean different things to different people. But the question What is the average mass of an apple? is a scientific question because the word mass always has the same meaning. This question can be answered by measuring apples and analyzing the results. Scientists ask questions based on their own observations or on the scientific ideas of others. The chart below lists some common phrases used in scientific questions. Common Phrases Used in Scientific Questions What is...? What causes...? How does...? When...? How long...? Why...? What happens if...? How are two things alike and/or different...? Which works better...? What is the best way to...? 8

6 During your studies, you will form many scientific questions based on your own observations. Imagine that you have just made popcorn in a microwave oven. You are disappointed to find that nearly half the kernels in the bag did not pop. This disappointment may lead you to ask one or more of the following questions: What is the best cooking time for a bag of popcorn prepared in the microwave? Does moisture content affect the number of kernels that pop? Which brand of popcorn yields the greatest volume of popcorn? Each of these questions is precise and can be answered through observation, measurement, testing, or analysis. Thus, each is a good and valid scientific question. Forming a Hypothesis An observation can lead a scientist to ask many questions. The questions, in turn, may then lead the scientist to a hypothesis. A hypothesis is a possible answer to a scientific question. A hypothesis is not a wild guess about the answer to a question. It is a statement based on reasoning, experience, or research. Most scientists review the work of others after asking their questions. Sometimes the research answers a scientist s question. Sometimes the information helps the scientist form a hypothesis. When you form a hypothesis, keep these points in mind: Your hypothesis should be based on observations and on logical reasoning. Your hypothesis should explain something in the natural world. You should be able to test your hypothesis. Different Questions and Investigations Each scientific question is different. Scientists use different procedures and design different kinds of investigations to answer different kinds of questions. A procedure is a step-by-step plan that guides an investigation. Many questions are best investigated in a laboratory. Suppose scientists want to determine how temperature affects a substance. First, they form a hypothesis. Then they design and conduct an experiment. An experiment is a carefully controlled procedure used to test a hypothesis. You will learn more about the tools and processes used in the laboratory in lessons throughout this book and by reading and conducting the investigations. 9

7 Some scientific questions are best answered through field studies investigations carried out in a natural setting. For example, scientists observe gorillas in the wild to learn about their behavior. Some investigations combine field study and lab work. Suppose scientists want to learn how a factory affects a nearby wetland. They observe the plants and animals living in the wetland. They also collect samples of water and soil. In their lab, the scientists test the samples for factory waste. Some things in nature are too small, too big, too far away, or too dangerous to investigate in a lab or in the field. Models help scientists investigate such things. A model is a representation of an object, system, or process. For example, scientists use computer models to study hurricanes. Scientists also use physical models. One group of scientists has used a model of a shark to study how sharks move through water. Using Data to Draw Conclusions As you can see, scientific inquiry has many forms. The first step is to ask a scientific question. The next step is to choose the best type of investigation to answer the question. Then a scientist must carry out the investigation. As scientists conduct investigations, they collect and record many types of data. Data are facts and information gathered during an investigation. Some data are observations made with the senses. Other data are measurements that are made using tools. You will learn about measurements and some important tools of science in the next lesson. After scientists gather data, the next step is to analyze them. To analyze data means to study them carefully to look for patterns and trends. Then the scientists form a conclusion. A conclusion is a statement that summarizes and explains the results of an investigation. Scientific conclusions state whether the data support the hypothesis. If the hypothesis is not supported, the investigation may be repeated or changed. A hypothesis that is not supported may be rejected. However, a rejected hypothesis is useful because it may lead to a new question, a new hypothesis, and more investigation. 10 Chapter 1: Practices of Science

8 Lesson 1: Scientific Inquiry Focus on Inquiry Scientific inquiry begins with a question that is based on observations or on the ideas or research of others. Often, this question leads to the formation of a hypothesis. Imagine you are watching the news. The top story deals with the weather and shows trucks spreading salt on a snow-covered road. This leads you to ask: How does salt affect the temperature at which water freezes? Based upon your observations, you state this hypothesis: Adding salt to water lowers the temperature at which the water freezes. Now try this. Complete the first column of the chart by writing your own scientific questions in the spaces provided. For each of your questions, complete the second column by writing a hypothesis. HINT: Check the quality of your hypotheses by making sure each meets the three points listed in the lesson. Scientific Questions and Hypotheses 1. Scientific Question Hypothesis

9 Lesson Review 1. Which of the following is not an example of a scientific question? A. Why is that dog limping? B. How long will it take to get there? C. Where did you put the book? D. What will happen if I add more salt? 2. What must be true of any hypothesis? A. It must be proven correct. B. It must be testable. C. It must not be based on observations. D. It must provide the answer to a scientific question. 3. Which represents the correct sequence a scientist may follow at the start of a scientific investigation? A. A scientist forms a hypothesis, then makes an observation and asks a question. B. A scientist makes an observation, then forms a hypothesis and asks a question. C. A scientist asks a question, then forms a hypothesis and makes observations. D. A scientist makes an observation, then asks a question and forms a hypothesis. 4. Which question would require a field study to answer? A. Which fertilizer produces the largest orchid flowers? B. In which part of a forest are there the most maple trees? C. Which brand of popcorn contains the most salt per serving? D. How does changing the temperature of water affect how ice floats in the water? 12 Chapter 1: Practices of Science

10 Chapter 1 Lesson 2 Scientific Tools and Measurement Objectives: , , Key Words hand lens microscope binoculars telescope metric system length metric ruler meterstick volume graduated cylinder mass balance spring scale force weight temperature thermometer Getting the Idea Scientists use tools to collect, analyze, organize, and record data. It is important to know how to choose and use the right tool for what you are studying. Using Tools to Make Observations As you carry out an investigation, you might need to look at some things very closely. A hand lens can help you. A hand lens is a tool that makes small objects appear larger. It would be a good tool for observing mineral grains in a rock or details of a butterfly s wing. Many things that scientists study are too small to observe with a hand lens. Suppose you want to observe the tiny living things in a drop of pond water. Then you must use a microscope a tool that makes very tiny objects appear much larger. Your classroom microscopes are light microscopes. They can make an object appear up to 2000 times its actual size. With a light microscope, you can view things as small as bacteria, algae, protozoa, and the cells of plants and animals. Viruses, molecules, and atoms are too small to observe with a light microscope. To study those things, scientists must use electron microscopes, which use electrons instead of light to create images. To observe a distant object, such as a bird in a tree, you can use binoculars. The lenses in binoculars make faraway things look closer. To view something very far away, such as another planet, you must use a telescope. Lenses and mirrors in telescopes make distant objects appear many times closer. Some telescopes are so powerful that scientists can use them to study distant stars. Hand lens Microscope Binoculars Telescope 13