Chemistry Student Name. Teacher Name

Transcription

1 Chemistry Student Name Teacher Name 1

2 Tops Objective: o Use the materials given to make a top that spins for the longest amount of time. Materials: o Paper Plate (can cut to any size) o Duct Tape o Up to 8 Pennies o Pencil (can manipulate size) Rules: You can use either side of the pencil (eraser or point) You must use at least one penny. In order to be eligible, the top must spin for a minimum of 10 seconds. You only get one paper plate!! Plan before you cut!! What are some qualities you should consider before making your top? An independent variable is the variable you have control over, that you can manipulate. What are the independent variables in this experiment? A dependent variable is the variable that changes because you have changed the independent variable. What is the dependent variable in this experiment? This is an experimental design activity. What do you think that means? 2

3 Metric Conversions Name Fill in the boxes in the stair step diagram. Try these conversions, using the ladder method mg = g 1 L = ml 160 cm = mm 14 km = m 109 g = kg 250 m = km Compare using <, >, or =. 56 cm 6 m 7 g 698 mg T. Trimpe

4 Metric Conversions Name Write the correct abbreviation for each metric unit. 1) Kilogram 4) Milliliter 7) Kilometer 2) Meter 5) Millimeter 8) Centimeter 3) Gram 6) Liter 9) Milligram Try these conversions, using the ladder method. 10) 2000 mg = g 15) 5 L = ml 20) 16 cm = mm 11) 104 km = m 16) 198 g = kg 21) 2500 m = km 12) 480 cm = m 17) 75 ml = L 22) 65 g = mg 13) 5.6 kg = g 18) 50 cm = m 23) 6.3 cm = mm 14) 8 mm = cm 19) 5.6 m = cm 24) 120 mg = g Compare using <, >, or =. 25) 63 cm 6 m 27) 5 g 508 mg 29) 1,500 ml 1.5 L 26) 536 cm 53.6 dm 28) 43 mg 5 g 30) 3.6 m 36 cm T. Trimpe

5 Part One: Describing Chemical Reactions Chemistry that Applies Michigan Dept of Education Cluster 1 5

6 SECTION 1.1 MATTER HAS MASS AND VOLUME. Reading Study Guide A BIG IDEA Everything that has mass and takes up space is matter. KEY CONCEPT Matter has mass and volume. Vocabulary matter anything that has mass and takes up space mass how much matter something contains weight the downward pull of an object because of gravity volume the amount of space something takes up CHAPTER 1 Introduction to Matter Review 1. List two tools a scientist might use. Take Notes I. All objects are made of matter. (p. 9) 2. Fill in the combination notes for the main idea shown. Copyright by McDougal Littell, a division of Houghton Mifflin Company MAIN IDEA DETAIL NOTES 1. All objects are made of matter. A. Matter is what makes up all objects and organisms. 3. In the table below, underline everything that is made of matter. B. Matter is. C. Two things that are not matter are. a book an idea light a feeling a chair a sound a mountain air MATTER AND ENERGY, CHAPTER 1, READING STUDY GUIDE A 13 6

7 II. Mass is a measure of the amount of matter. (p. 10) 4. Fill in the four-square diagram for mass. CHAPTER 1 Introduction to Matter Definition How much matter something contains. Examples MASS Characteristics Nonexamples A B. Measuring Mass and Measuring Weight (p. 10) 5. Circle the object on each balance that has more mass. MILK 6. Do mass and weight mean the same thing? Remembering that gravity is less on the Moon than it is on Earth, which measurement mass or weight changes on the Moon? III. Volume is a measure of the space matter occupies. (p. 11) 7. Fill in the four-square diagram for volume. Definition Examples the size of a basketball VOLUME A B. Determining Volume by Formula and Determining Volume by Displacement (pp ) 8. The volume of an object can be determined using the formula l w h. What do the letters (variables) stand for? Characteristics Nonexamples the weight of a basketball Copyright by McDougal Littell, a division of Houghton Mifflin Company 9. What is another way to determine an object s volume? 14 MATTER AND ENERGY, CHAPTER 1, READING STUDY GUIDE A 7

8 CHAPTER 1 Introduction to Matter SECTION 1.1 MATTER HAS MASS AND VOLUME. Reinforcing Key Concepts BIG IDEA Everything that has mass and takes up space has matter. KEY CONCEPT Matter has mass and volume. 1. All objects are made of matter. Matter is what makes up all of the objects and living organisms in the universe. Matter is anything that has mass and takes up space. What is matter made of? Name two things that are not made of matter. 2. Mass is a measure of the amount of matter. When you measure mass, you compare the mass of the object with a standard amount, or unit of mass. When you measure weight, you are measuring the downward pull on an object due to gravity. Look at the two pictures below showing a bowling ball being measured for weight and for mass. In which picture is the bowling ball s mass being measured? How can you tell? A 3. Volume is a measure of the space matter occupies. The amount of space that matter in an object occupies is called an object s volume. A bowling ball and a basket ball take up approximately the same amount of space, therefore, the two balls have about the same volume. Volume is calculated by multiplying the length, width, and height of an object. You would like to calculate the volume of a brick. The brick is 32 cm long, 20 cm high, and 15 cm wide. Use the formula V = lwh to calculate the volume of the brick. If you used the displacement method to determine volume, how many milliliters would the brick take up? B Copyright by McDougal Littell, a division of Houghton Mifflin Company 20 MATTER AND ENERGY, CHAPTER 1, REINFORCING KEY CONCEPTS 8

9 Introduction to Chemistry Chem4Kids Please log on to - Click on Matter Matter Overview Read through all the information on this page. Summarize matter in three short phrases o o o At the bottom of the page: o Click on Next Page on Matter. It will bring you to States of Matter. States of Matter Read through all the information on this page. Each state is also known as a. What physical force commonly causes elements and compounds to move from one phase to another? At the bottom: Click on Next Page on Matter. It will bring you to Changing States of Matter Changing States of Matter Read through all the information on this page. What is required for matter to change from one state to another? o o What happens to water molecules as they approach freezing, and melting points? At the bottom: Click on Next Page on Matter and read the section called Liquid to Gas and Back to Liquid. Then, click on Next Page on Matter and It will bring you to Chemical Changes Versus Physical Changes. 9

10 Chemical Changes Versus Physical Changes Read through all the information on this page. Describe and give an example of each type of change. o Chemical o Physical At the bottom: Click on Next Page on Matter. It will bring you to Solid Basics. Solid Basics Read through all the information on this page. What are some characteristics of a solid? o o How do the atoms in a solid behave? At the bottom: Click on Next Page on Matter. It will bring you to Liquid Basics. Liquid Basics Read through all the information on this page. What are some characteristics of a liquid? o o How do the molecules in a liquid behave? At the bottom: Click on Next Page on Matter and read the section called Evaporation of Liquids. Then, click on Next Page on Matter and It will bring you to Looking for a Gas. 10

11 Looking for a Gas Read through all the information on this page. What are some characteristics of a gas? o o How do the molecules in gas behave? 11

12 Lesson 1: Mixing It Up Each morning we begin our day by mixing things. It may be our favorite cereal and milk, toast with butter, or cream and coffee. It doesn t end there. As the day continues, we use a wide array of mixed substances such as foods, hair sprays, liquid soaps, fertilizers for plants, gasoline and oil for the lawn mower, glue, detergents for washing clothes, and the flour, eggs, sugar and baking powder for making cakes. Mixing substances together is something we do (or have done for us) all the time. Asking questions about these mixtures will help us to look more closely at what is happening when things are mixed. 1. What types of things do you mix on a daily basis? Make a list of 5 combinations that you mix together every day. 2. Examine your materials. Starting Substances Common Name Description 12

13 3. Pick four (4) combinations of two (2) substances. List them in the left column below. Mix each of the combinations. Write a description of what you saw when the two substances were mixed in the middle column. Write a description of the substance that was created when the two were mixed in the right column. Substances to mix Description of What Happened Description of Ending Substance 4. Pick four (4) combinations of three (3) substances. List them in the left column below. Mix each of the combinations. Write a description of what you saw when the three substances were mixed in the middle column. Write a description of the substance that was created when the three were mixed in the right column. Substances to mix Description of What Happened Description of Ending Substance 13

14 Think and Write: 5. Do you think any of the demonstrations DID NOT produce new substances? How can you tell? 6. Do you think any of the demonstrations DID produce new substances? How can you tell? 14

15 Lesson 2 Is it a New Substance? Objective: To perform, observe, and describe a reaction in order to find evidence for the formation of new substances. Reaction #1: Rusting Iron Procedures: 1. Examine your group s 2 starting substances, steel wool and vinegar, and write a description in the chart on the next page. Use at least 3 descriptive terms from our list. 2. Place the steel wool in a beaker. Pour enough vinegar over the steel wool to cover it. Swirl the wool and vinegar making sure that the vinegar has come in contact with all the steel wool. The vinegar will remove an oily protective coating from the steel wool and leave the thin strands of steel wool. 3. Remove the steel wool from the beaker and blot it very dry with a paper towel. Loosen the strands of the steel wool. Place it in a plastic cup and observe what happens after 10 minutes. Record your observations in the chart. Reaction #2: Baking Soda and Vinegar Procedures: 1. Observe the 2 starting substances, baking soda and vinegar, and write a description below for each. Be sure you use at least 3 descriptive terms for each. 2. Watch as the baking soda and vinegar are combined in a beaker. Record your observations in the chart on the next page. 15

16 Reactions Starting Starting Observations Ending substance #1 Substance #2 Substance Reaction #1 Rusting Iron Reaction #2 Baking Soda and Vinegar Conclusion and Reflection: 1. Based on your observations, what ending substance is/are formed for both reactions? Reaction #1: Reaction #2: 2. Based on what you saw in this lab, do you think new substances can be formed when combining and mixing different substances together? 3. If you think any new substances were formed in either reaction, how could this be explained? Where would the new substances come from? 16

17 SECTION 1.2 MATTER IS MADE OF ATOMS. Reading Study Guide A BIG IDEA Everything that has mass and takes up space is matter. KEY CONCEPT Matter is made of atoms. Vocabulary atom the smallest basic unit of matter molecule two or more atoms bonded together CHAPTER 1 Introduction to Matter Review 1. Fill in the concept map for matter. Matter has has Copyright by McDougal Littell, a division of Houghton Mifflin Company Take Notes I. Atoms are extremely small. (p. 16) 2. Fill in the combination notes for the main idea shown. MAIN IDEA DETAIL NOTES 1. Atoms are extremely small. A. An atom is the smallest basic unit of matter. B. The idea of atoms dates back to. C. Today scientists know of more than. A. Atoms (p. 17) 3. Can you see an individual atom? Why or why not? MATTER AND ENERGY, CHAPTER 1, READING STUDY GUIDE A 23 17

18 4. Which of the objects below is made of atoms? How do you know? Copyright by McDougal Littell, a division of Houghton Mifflin Company CHAPTER 1 Introduction to Matter B. Molecules (p. 18) 5. Fill in the four-square diagram with information about molecules. Definition Characteristics can be made of atoms that are different or alike Examples MOLECULE Nonexamples a hydrogen atom II. Atoms and molecules are always in motion. (p. 19) 6. Fill in the combination notes for the main idea shown. MAIN IDEA 1. Atoms and molecules are always in motion. DETAIL NOTES A. Dust particles show that. B. Food coloring shows that water molecules, also, are. C. Even molecules in solid objects. 24 MATTER AND ENERGY, CHAPTER 1, READING STUDY GUIDE A 18

19 CHAPTER 1 Introduction to Matter SECTION 1.3 MATTER COMBINES TO FORM DIFFERENT SUBSTANCES. Reading Study Guide A BIG IDEA Everything that has mass and takes up space is matter. KEY CONCEPT Matter combines to form different substances. Vocabulary element a substance with only one type of atom compound a substance with atoms of more than one type bonded together mixture a combination of one or more substances that can be separated physically Review 1. What is all matter made of? Take Notes I. Matter can be pure or mixed. (p. 21) 2. Fill in the combination notes for the main idea shown. MAIN IDEA DETAIL NOTES 1. Matter can be pure or mixed. A. Often the difference between pure and A. Elements and Compounds (pp ) mixed substances can only be seen at the molecular or atomic level. B. A pure substance has. C. The components of a pure substance can be either. D. Mixed substances have. 3. Bronze is made by combining the element copper with the element tin. Is pure bronze an element? Why or why not? Copyright by McDougal Littell, a division of Houghton Mifflin Company 34 MATTER AND ENERGY, CHAPTER 1, READING STUDY GUIDE A 19

20 4. Fill in the description wheel diagram for compound. table salt COMPOUND water CHAPTER 1 Introduction to Matter substance B. Mixtures and Comparing Mixtures and Compounds (pp ) 5. Fill in the four-square diagram for mixture. Definition Characteristics Copyright by McDougal Littell, a division of Houghton Mifflin Company Examples MIXTURE 6. Fill in the chart comparing mixtures and compounds. compound mixture Substances That Make It Up change to new substances Can Be Separated By physical means fixed II. Parts of mixtures can be the same or different throughout. (p. 25) 7. What is a heterogeneous mixture? What is a homogeneous mixture? Nonexamples table salt Proportions MATTER AND ENERGY, CHAPTER 1, READING STUDY GUIDE A 35 20

21 SECTION 1.4 MATTER EXISTS IN DIFFERENT PHYSICAL STATES. Reading Study Guide A BIG IDEA Everything that has mass and takes up space is matter. KEY CONCEPT Matter exists in different physical states. Vocabulary states of matter the different forms in which matter can exist solid a substance with a fixed volume and a fixed shape liquid a substance with a fixed volume but no fixed shape gas a substance with no fixed volume or shape CHAPTER 1 Introduction to Matter Review 1. What tiny particles make up matter? Take Notes I. Particle arrangement and motion determine the state of matter. (p. 27) 2. Fill in combination notes for the main idea shown. Copyright by McDougal Littell, a division of Houghton Mifflin Company MAIN IDEA 1. Particle arrangement and motion determine the state of matter. DETAIL NOTES A. Three states of matter: B. From one state to another, molecules do not. C. From one state to another, arrangement of molecules does. MATTER AND ENERGY, CHAPTER 1, READING STUDY GUIDE A 45 21

22 CHAPTER 1 Introduction to Matter II. Solid, liquid, and gas are common states of matter. (p. 28) 3. Each sketch shows the same substance in three different states. Below each sketch, write whether it is a solid, liquid, or gas. A. B. C. III. Solids have a definite volume and shape. (p. 30) 4. Fill in the combination notes for the main idea shown. MAIN IDEA 1. Solids have a definite volume and shape. DETAIL NOTES A. The molecules in a solid are in fixed positions and close together. B. Molecules can vibrate but do not C. The particles in some solids occur IV. Liquids have a definite volume but no definite shape. (p. 31) 5. How are molecules in a liquid arranged? V. Gases have no definite volume or shape. (p. 32) 6. What is the difference between molecules of a gas and molecules of a liquid? A B. Gas Composition and Gas Behavior (pp ) 7. Fill in the chart with information about how gases change in the given conditions. Change Result If temperature remains the same and pressure goes up, volume goes. Copyright by McDougal Littell, a division of Houghton Mifflin Company If volume remains the same and temperature goes up, If pressure remains the same and temperature goes up, pressure goes. volume goes. 46 MATTER AND ENERGY, CHAPTER 1, READING STUDY GUIDE A 22

23 Lesson 4: Does the Weight Change? Objective: Students will observe reactions involving physical changes such as crumpling, melting, dissolving and boiling; they will explore and discuss their thinking about the weight changes that occur. 1. Write and explain your prediction for each of the demonstrations listed below. Demonstration 1: Which weighs more, a tightly wadded ball of steel wool or the same steel wool stretched and pulled apart? Demonstration 2: How does the weight of a glass of water with an ice cube in it change as the ice cube melts and eventually disappears? Demonstration 3: Observe a teaspoon with sugar and a glass of warm water. Then stir the sugar into the glass of warm water until it has dissolved. How does the initial weight of the teaspoon of sugar and the glass of water compare to the weight of the dissolved sugar and water? Demonstration 4: How would the weight change if you boiled a beaker of water for 10 minutes? 23

24 1. Share and debate your predictions with your team. Your predictions don t have to be the same as those of your team members 2. Choose one spokesperson for your team. 3. Share your predictions and reasoning of your team with the whole class. Make sure you tell the class if not everyone agrees on any of your predictions or reasons. 4. Get a class tally for each prediction. How many students think the weight would increase, decrease or stay the same? Steel Wool Water & Ice Cube Water & Sugar Boiled Water Cru mpl ed Stre tch ed Same Same Same Same 5. How could you test your predictions, and prove or disprove them? 24

25 Lesson 5: Gathering Evidence About Weight from Experiments How can we test the predictions you made in the last lesson? Did someone say, By actually weighing the materials? Sure. In this lesson, you will perform the same activities that your teacher demonstrated. You will use a balance or scale to actually weight the substances and then compare these results to your predictions. Key Question: How do your predictions compare to the actual changes in weights of the substances? Demonstration 1: Which weighs more, a tightly wadded ball of steel wool or the same steel wool stretched and pulled apart? Substance Steel Wool Tightly wadded steel wool Stretched steel wool Difference Demonstration 2: How does the weight of a glass of water with an ice cube in it change as the ice cube melts and eventually disappears? Substance Beginning Weight Ending Weight Difference Ice / Water Demonstration 3: Observe a teaspoon with sugar and a glass of warm water. Then stir the sugar into the glass of warm water until it has dissolved. How does the initial weight of the teaspoon of sugar and the glass of water compare to the weight of the dissolved sugar and water? Substance Beginning Weight Ending Weight Difference Sugar / Water Demonstration 4: How would the weight change if you boiled a beaker of water for 10 minutes? Substance Beginning Weight Ending Weight Difference Boiling Water 25

26 Think and Write: 1. Did your results help to prove or disprove your predictions? 2. What must happen during any change for the weight of the materials to increase or decrease? 3. In which of the experiments did the weight decrease significantly? 4. What was different about that experiment from the others where there was no weight change? 5. What are all substances made of? Use as much detail as you can. 6. Did the weight change for each of the following materials? Why or why not? Use molecules in each explanation. Draw a picture that shows what is happening to the molecules. a. Steel wool b. Water and ice c. Sugar and water d. Boiling water 26

27 7. Are these changes physical or chemical changes? Explain your answer. 8. Predict what would happen to the weight of a cold glass of water on a humid summer day? Explain your prediction. 9. Predict what would happen to the weight of a car that gets very rusty over several years. Explain your prediction. 27

28 SECTION 2.1 MATTER HAS OBSERVABLE PROPERTIES. Reading Study Guide A BIG IDEA Matter has properties that can be changed by physical and chemical processes. KEY CONCEPT Matter has observable properties. Vocabulary physical property a characteristic of a substance that can be observed without changing the substance density a measure of how much matter is in a given volume of a substance physical change a change in any physical property of a substance chemical property a property that describes how a substance combines with another to form a new substance chemical change the change of one substance into another substance Review 1. Fill in the concept map for matter. CHAPTER 2 Properties of Matter MATTER Copyright by McDougal Littell, a division of Houghton Mifflin Company Take Notes has is made of exists in I. Physical properties describe a substance. (p. 41) 2. Fill in the magnet word diagram for the main idea shown. observed without changing identity PHYSICAL PROPERTIES volume mass MATTER AND ENERGY, CHAPTER 2, READING STUDY GUIDE A 85 28

29 A. Physical Properties and Density (pp ) 3. Fill in the magnet word diagram for the main idea shown. measurement DENSITY units of g/cm 3 4. The formula for density is D m/v. What is the density of a wooden board that has a mass of 400 g and a volume of 500 cm 3? CHAPTER 2 Properties of Matter B. Physical Changes (p. 44) 5. Fill in the main-idea web for the main idea shown. In a physical change, the substance A change of state is an example itself does not. of a. A physical change is a change in any physical property of a substance. Example. II. Chemical properties describe how substances form new substances. (p. 46) 6. Why is the ability to burn defined as a chemical property instead of a physical property? A B. Chemical Properties and Changes and Signs of a Chemical Change (pp ) 7. List and describe four signs of a chemical change. Copyright by McDougal Littell, a division of Houghton Mifflin Company 86 MATTER AND ENERGY, CHAPTER 2, READING STUDY GUIDE A 29

30 Lesson 6: Does the Weight Change in Chemical Reactions? Objective: Students will observe and make predictions about whether the weight changes in a chemical reaction. Then they will perform an experiment to test their hypothesis. Key Question: How can you predict if the weight of a substance will change during a chemical reaction? PART ONE: PREDICTION (Open System) Do you think a new substance was formed when you mix baking soda & vinegar? Why or why not? Prediction: Did the weight increase, decrease, or remain the same during this reaction? Explain your reasoning. PART TWO: EXPERIMENT Plan, as a group, how to conduct an experiment to prove your prediction. Write out your plan in steps on the table below, Open System Steps to Conduct Experiment Measurements Before Measurements After 1. Put on safety glasses. 30

31 Closed System Steps to Conduct Experiment Measurements Before Measurements After 1. Put on safety glasses. PART THREE: ANALYSIS 1. Did your results of the baking soda & vinegar in the open system help prove or disprove your predictions? 2. Were there any substances that left the reaction or that were added to the reaction? o Open System o Closed System 3. What is the difference between an open system and a closed system? 31

32 4. Did the weight change during this experiment? If so, how? o Open System o Closed System 5. How were the ending substances different from the starting substances? 6. Does this indicate that the change was a physical change or a chemical change? 32

33 SECTION 2.2 CHANGES OF STATE ARE PHYSICAL CHANGES. Reading Study Guide A BIG IDEA Matter has properties that can be changed by physical and chemical processes. KEY CONCEPT Changes of state are physical changes. CHAPTER 2 Properties of Matter Vocabulary melting process by which a solid becomes a liquid melting point temperature at which a substance melts freezing process by which a liquid becomes a solid freezing point temperature at which a liquid becomes a solid; same as melting point evaporation process by which a liquid becomes a gas sublimation process by which a solid changes directly to a gas boiling process by which a liquid becomes a gas and produces bubbles boiling point temperature at which a liquid boils condensation process by which a gas changes state to become a liquid Review 1. For each sentence, circle the word that completes the sentence correctly. Chemical changes (produce/do not produce) new substances. Physical changes (produce/do not produce) new substances. Take Notes I. Matter can change from one state to another. (p. 50) II. Solids can become liquids, and liquids can become solids. (p. 51) 2. Give two examples of liquids that can change to solids. A B. Melting and Freezing (pp ) 3. Fill in the word triangle diagrams for melting and freezing. The ice cream was melting. The ice cream was freezing. Copyright by McDougal Littell, a division of Houghton Mifflin Company melting: freezing: 96 MATTER AND ENERGY, CHAPTER 2, READING STUDY GUIDE A 33

34 4. What happens when the temperature of a solid reaches its melting point? What happens when the temperature of a liquid reaches its freezing point? III. Liquids can become gases, and gases can become liquids. (p. 53) 5. Fill in the main-idea web for gases and liquids. Evaporation occurs. Boiling also results in. Condensation occurs. Liquids can become gases, and gases can become liquids. A B. Evaporation, Boiling, and Condensation (pp ) 6. How are boiling, evaporation, and sublimation the same? CHAPTER 2 Properties of Matter 7. Below each picture, write evaporation, condensation, boiling, or melting. Copyright by McDougal Littell, a division of Houghton Mifflin Company A. B. C. D. MATTER AND ENERGY, CHAPTER 2, READING STUDY GUIDE A 97 34

35 The Behavior of Matter The following activity will allow you to observe the behavior of matter and help you to understand the following concepts: condensation, expansion, diffusion, evaporation, melting, and solidification. Demonstration #1- Place a drop of food coloring into very cold water and another drop into very hot water. Explain the difference in behavior. Demonstration #2 Heat a microscope slide. Place one drop of alcohol on the heated slide. Explain what you observed. Demonstration #3 Place ice water into a beaker. Breathe on the side of the beaker. Explain what you think the water molecules in your breath are doing. Demonstration #4 Spray some perfume into the air. What are the particles doing? Demonstration #5 Observe a burning candle. What forms at the top of the candle? What happens after the flame is put out? 35

36 Demonstration #6 Place a balloon over a flask filled with some water. Place the flask over an open flame. Describe what you see. Demonstration #7 Ball and Ring Demonstration. Describe what you see. Why did this occur? Relate each term to an every day experience. Term condensation Example evaporation expansion melting solidification diffusion 36

37 Lesson 8: Do Gases Have Weight? By the end of the last lesson, you probably decided that all the little bubbles that formed in the two reactions contained some kind of invisible gases. As the bubbles broke, the gases escaped to the surrounding air. If you knew for sure whether the gases have weight, then you would know how to make your predictions. How could you design an experiment that would test this out? Key Question: Do gases have weight? How can you find out? How does the weight of the starting substances compare to the weight of the ending substances when gases are formed and given off in a reaction? Open System This demonstration is done first as an open system that is, the stopper / balloon is left off the container. The Alka-Seltzer is fizzing in an open container. 1. Write your prediction about weight change increase, decrease, or remain the same for this reaction. Also, be sure to write a reason for your prediction. Your teacher will prepare the apparatus for a class demonstration. Weight Before Weight After 2. Does the experiment support your prediction? Any new thoughts about what happened to weight? Share your ideas with your group. 37

38 Closed System Now you teacher will repeat the demonstration as a closed system. When there s a top on a container, so that nothing can get in or out, it is called a closed system. The Alka-Seltzer will be fizzing in a closed jar. 3. Write your prediction about weight change increase, decrease, or remain the same for this demonstration and the reason for your prediction. Your teacher will now prepare the experiment as described above, but this time the container will be secure. Weight Before Weight After 4. What do you think will happen to the weight when the stopper / balloon is taken off? Write your prediction and the reason for your prediction. 5. Now, remove the stopper / balloon. What happens? Why? 38

39 Lesson 8: Do Gases Have Weight Think & Write Questions 1. Does the experiment support your prediction for the open system reaction? 2. Does the experiment support your prediction for the closed system reaction? 3. Try to explain what happened to cause the weight change in the open system. 4. Try to explain what happened which prevented a change in weight in the closed system. 5. Try to explain what happened when the bottle cap was opened. 39

40 6. What did you learn? Do gases have weight or not? What evidence do you have? 7. The reactants are ALL the substances you started with including any invisible gases, and the products are ALL the substances that were formed, including any invisible gases. Are they different in an open system than they are in a closed system? 8. And now the big question, the one you ve been trying to answer all along: How does the weight of the products compare to the weight of the reactants? 40

41 Lesson 9: Rusting Metal and the Deflating Balloon You learned in the last two lessons that chemical reactions sometimes produce invisible gases. The gases often make bubbles if they are produced inside a liquid. When the bubbles pop, the gases fly off into the atmosphere. Key Question: Can invisible substances like oxygen and other gases be involved in chemical reactions in any other way (not just as products)? Here is an activity to start you thinking about these questions. Steel Wool & Vinegar Obtain a piece of steel wool that will form a ball about the size of a pingpong ball. Dip it in vinegar very briefly just to clean off the protective coating. Dry it very thoroughly by pressing it between several layers of paper towel. Pull the strands apart to loosen them and then drop the steel wool into a clean flask. Squeeze all the air out of a balloon and then stretch this deflated balloon over the top of the Erlenmeyer flask. Observe for a few minutes and then set it aside while you answer the following question: 1. What are some very important properties of gases in addition to the fact that they are usually invisible? Refer back to the last lesson if you need help on this answer. Now observe the reaction again. 2. What happened to the balloon in this experiment? 3. What is this evidence for? 41

42 Funnel and Balloon Obtain a funnel and a beaker half filled with water, such that the large end of the funnel will fit into it. Lower the funnel gradually into the beaker all the way to the bottom. not? 4. Does water enter the funnel? Why or why Now repeat the process, but this time hold your finger over the small end of the funnel and immerse it into the beaker of water. Lower it gradually all the way to the bottom. 5. Does water enter the funnel? Why or why not? Now, with the funnel at the bottom of the beaker, remove your finger and observe what happens. Try this several more times by placing your finger over the end of the funnel when it is only partly immersed and see what happens. Place a balloon tightly over the small end of the funnel by first squeezing all the air out of the balloon and then pulling it over the end of the funnel. Be careful not to rip the balloon. Place the large end of the funnel in the water. Lower it gradually. 6. What happens? Squeeze the balloon slowly but firmly and see what happens. 7. What is causing this to happen? 42

43 Lesson 9: Rusting Metal and the Deflating Balloon Think & Write Questions 1. What invisible substance was in the funnel when you first placed it in the water? 2. When you placed your finger over the end of the funnel and pushed it into the water, no water entered the funnel. How would you explain this? 3. How would you explain what happened when you removed your finger from the funnel and water rushed in? 4. Why did the balloon inflate? 5. How can you explain your observations when you squeezed on the balloon? This is a demonstration about air. It can push on water. Water can push on it. If you get some soda in a straw and blow on the straw, the soda flies across the room. The air in your mouth pushed on the air in the straw, which pushed on the soda. Air is a substance. You can t see it, but it pushes on things. 43

44 6. If you put a straw into a plastic bag filled with air, and started to suck the air out, what would happen to the plastic bag? Why? Now look at your steel wool experiment. 7. Why was the balloon sucked into the flask when the steel wool rusted? 8. Did the air in the flask just disappear? Did it leak out? What happened to it? 44

45 Lesson 10: Does Rusting Need Air? What happened to make the balloon get sucked into the beaker? Here is an activity that will help you figure out what happens with air and rusting. You will start by making a prediction. A. Observe the flask with the steel wool reaction you saved from the last lesson. Make a prediction about what happened to the weight of the steel wool increase, decrease or remain the same. B. Write your prediction and the reasons why you think this happened. Once again, verifying your prediction is very tricky because if there were any gases involved in the reaction the weight of gases is very small. The procedure for reacting the steel wool must be changed slightly to make the steel wool react more, and therefore have a bigger change in weight that can be measured. This time the steel wool will be burned intensely with a lighter to cause a reaction that is very similar to rusting, only faster and more intense. More about that after you observe the reaction. Your teacher will prepare a demonstration using a flame and enough steel wool so that when compacted and rolled into a ball, it will be about the size of a ping-pong ball. Make a prediction about how the weight might change if the steel wool is heated. Weight of Steel Wool Before Heated Weight of Steel Wool After Being Heated Difference 45

46 Lesson 10: Does Rusting Need Air? Think & Write Questions 1. Write a description of the product. 2. What happened to the weight after the steel wool was burned? Did this surprise you? Did you expect something else? 3. Did the steel wool have something added to it or something taken away from it during the chemical reaction? 4. What, besides the steel wool, do you think might be involved in the reaction? 5. Remember, this reaction is similar to that of the rusting of steel wool. The same reactants are needed, and very similar products are formed. Can you now explain what happened with the steel wool rusting under the balloon? 46

47 6. What do you think happened to the weight of steel wool when it rusted? Explain your answer using the data you collected in the experiment with the balloon: the observation that the balloon was sucked in to the beaker (what does this mean about the air around the steel wool?). 7. Why might your little brother think that matter was created in this experiment? 47

48 Lesson 12: What Makes One Substance Different From Another? Key Question: What makes substances different even though sometimes they may look alike? Think about this last question for a minute. What are some differences between vinegar and water? What are some differences between baking soda and sugar? Between hydrogen gas and oxygen gas??????? The basic difference between substances, one that chemists have figured out over the last several centuries, is that different substances are made up of different kinds of molecules. 1. Write what you remember about molecules. Chemists have come to understand that common substances in our environment really all substances, common or not when they are magnified millions of times, are composed of different kinds of molecules. Water, for example, has its own kind of molecule, which we often refer to as H2O. Sugar has its own kind of molecule. a water molecule Vinegar is made up of its own special kind of molecule. Oxygen is made up of still another kind of molecule. Carbon dioxide is composed of molecules different from oxygen. So are aluminum, and iron, and copper, gold and many, many, many other solids, liquids and gases. Take a chunk of ice. Magnify it millions of times, and you would see water molecules joined together into sort of a cage-like structure, jiggling a little, but 48

49 staying in the same place. Solids are made of molecules that are close together in neat, orderly, regular arrangements. When ice gets warmer, it becomes liquid water. The molecules jiggle faster as the ice gets warmer, until they break free from the forces that hold them together as solids. As a liquid, the molecules are moving freely within the container, sliding around past each other. But nothing about the individual molecules has changed. They are still H2O. When water is heated, it boils and becomes water vapor. The molecules are given increased speed by the heat, and fly off the surface of the water, into the air. As gaseous water vapor, molecules are very far apart. But they are still H2O molecules. Whether a substance is in the solid, liquid or gaseous phase has only to do with how the molecules are arranged and how they move. If you heat a solid, it changes to a liquid and, if you heat it more, the liquid changes to a gas. The opposite is also true. If you cool a gas, it changes to a liquid and, if you cool it more, the liquid becomes a solid. The molecules themselves are the same in all three forms. They have simply gone into different arrangements because of the increased speed (when heated) or decreased speed (when cooled.) And because the molecules are still the same, no new substances are formed. 2. Draw a picture of what you think pure ice, water and water vapor would look like if magnified millions of times. 3. a. How could you get a solid to change to a liquid or a liquid to a gas? Give an example of each. b. How could you get a gas to change to a liquid or a liquid to a solid? Give an example of each. c. Would your methods work for butter? For chocolate? for a metal such as aluminum? Explain. 49

50 4. All the food we eat (fruits, vegetables, milk, juice, meat, bread, etc.) contains large amounts of water. If fresh fruits or vegetables are left around for a while, they begin to wither and dry out. What kind of change is this? Use molecules to explain why you think this. 5. When an egg white is cooked, it goes from sort of a liquid to some sort of a solid. Is this a change of state or some other kind of change? (This is really a tough one, so here s a hint. If water changes from liquid water to solid ice, do you heat it or cool it? When the egg white changes from liquid to solid, do you heat it or cool it?) Different Kinds of Molecules A gold ring can be melted into liquid gold, and then poured into a mold to make a new ring. Its gold molecules never change in this process. But if you poured water into the ring mold, and froze it, would it come out as gold metal? Why not? Every pure substance has its own special kind of molecule, different from the molecules of all other substances. How might a vinegar molecule be different from a water molecule? How might a salt molecule be different from a sugar molecule? Brainstorm answers to these questions, and write them on the board. Then work through the following questions. They help explain how there can be so many different kinds of molecules in the world. 6. a. Think of all the letters of the alphabet. How many letters are there? b. What can you build out of letters? c. How many words can you build from the 26 letters of the alphabet? d. Where could you find a complete list of all these words? e. Are new words ever added to these lists? 50

51 LETTERS MAKE WORDS ESNESNON EKAM OSLA SRETTEL 7. a. Do all combinations of letters make words? b. Does it make a difference what order the letters are in? c. Does it make a difference if you add or take letters away? d. Think of an example that will illustrate each of these last 3 questions. Atoms Nature uses atoms as pieces to build hundreds of thousands of different substances much like the 26 letters of the alphabet are used to build hundreds of thousands of different words. Many of these atoms are familiar to you. Others have very strange names. The chart lists the most common atoms. 51

52 Think about how letters make words and use this information to answer the following questions. 8. How can all the different materials of the earth be made from only about 20 building blocks? 9. Where do you think you could find a complete list of all the different kinds of molecules? 10. Do all combinations of atoms make real molecules? 11. Does it make a difference what order the atoms are in when they form molecules? 12. Would it make a difference if you add atoms to a molecule or take them away? Like with words, where not all combinations of letters make a real word, not all combinations of atoms make real molecules. When atoms join together to form molecules, they must fit together, much like particular legs fit on certain chairs. Not all legs fit on all chairs; you must get the right leg to fit a given chair. In the same way, you must have the right atoms to fit together to make a certain molecule. You may have noticed that we are using a lot of models to talk about atoms and molecules. Why? Because atoms and molecules are so small that we cannot see them even under the most powerful microscope. So scientists use things we can see to help them understand how the things that we cannot see work. No model is ever perfect, so when using models it is important to think about how the model is similar to and how it is different from what it represents. Now it s your turn to be a scientist and think of a good model for atoms and molecules. 52

53 Try This: Consider bricks as a model for how atoms make molecules. List three things that can be built from bricks. Use the chart below to think about ways that objects made from bricks are like molecules, and ways that they are different. Circle the correct answers when necessary. Bricks A house is made out of smaller pieces called bricks. Bricks can be used to make many different objects, including. A house is made of only one kind of building block (the brick.) If someone adds bricks to the house (to build an addition) it is not the same house as it was before Molecules Molecules are made out of smaller pieces called. Atoms can be used to make many different molecules, including. Most molecules are made of: a) only one kind of atom, or b) different kinds of atoms. If somehow one or more atoms is added to a molecule, it is: a) just a larger molecule of the same substance, or b) a totally new and different molecule making a new substance. 13. Write a list of at least ten things in your classroom that are made of molecules. 14. Write a list of at least ten things in your classroom that are made of atoms. 15. What s the difference in these two lists? What s the similarity? Explain. 16. Is sand made of molecules? Is each sand grain a molecule? Why do you think what you said? 53

54 17. Is clay made of molecules? Why do you say that? 18. Is soup made of molecules? 19. How could you explain how soup is made of molecules? Fill in the blanks below, putting the letter for the correct part on the line. a. broth, vegetables, rice, maybe meat b. proteins, and proteins are molecules c. cell parts, like a nucleus, mitochondria, cytoplasm d. animal and plant cells Soup is made of 1. which are made of: 2. which are made of: 3. which are made of: 4. and molecules are made of: 5. In the next several lessons, you will build models of the substances involved in some of the reactions you have done. 54

55 Lesson 13: Atoms In, Atoms Out Decomposing Water Key Question: How can atoms and molecules be used to explain the formation of new substances? How can they be used to explain the Law of Conservation of Matter? A battery can be used to make bubbles appear under water. The water level went down as the bubbles were formed. How can atoms and molecules be used to explain the formation of bubbles from water? Decomposing Water 1. Write the common name of the reactant (the starting substance) on the data chart below. 2. You probably know the chemical formula for water. Write it on the chart. The formula for any substance is the shorthand way that chemists use to show the kind and number of atoms that are needed to make a molecule of that substance. Can you figure out what the formula for water means? The H stands for hydrogen, and there are 2 atoms of hydrogen in a molecule of water. The O stands for oxygen, and since there are no numbers beside it, there is only 1 atom of oxygen in the water molecule. 55

56 Now think about the products that were formed. What could they be? They were bubbles, of course, but what was in the bubbles? Since the water level went down, we might assume that the water changed into the bubbles. We know, though, that the water wasn t boiling, because it never got hot. So the bubbles couldn t have been water vapor. What else could they be? Here s a hint. Look at the types of atoms that make up a water molecule. Since water molecules are made up of only hydrogen and oxygen atoms, the substances formed inside the bubbles can only contain hydrogen and oxygen. Would it be possible to have carbon dioxide (CO2) as a product of this reaction? Why? So what substances are inside the bubbles? Did someone say Maybe there s oxygen gas inside some of the bubbles, and hydrogen gas in the other bubbles? Yes! The water molecule is coming apart and making hydrogen and oxygen molecules. Hydrogen gas is in the bubbles coming off one of the pencil leads, and oxygen gas is in the bubbles coming off the other lead. You can prove this by collecting the gases and conducting tests on them. The tests are easy. Hydrogen explodes with a loud pop when a burning piece of wood is placed in it. Oxygen makes a slightly burning (glowing) piece of wood burn very brightly. You need to collect these gases separately before you can test them. 3. On your chart, write the common name of the ending substances (the products.) In this case, they are oxygen gas and hydrogen gas. 4. Obtain a model-building kit and find the necessary pieces to build a water molecule. 5. Your teacher will tell you which colors represent which kinds of atoms. Try making a model of a water molecule. You need two hydrogen atoms (the same color) and one oxygen atom (a different color). Answer: Do all the models in the class look exactly alike? Why not? Chemists have found that both hydrogens attach on opposite sides of the oxygen, not to each other, like in the picture on the left. If your model has the two H hydrogens attached to each other, change it. Make two water molecules. 6. Draw a picture of your model of the water molecule on your data chart. 7. Label each atom or color it to show what kind they are. 56

57 8. Now build models of the ending substances. Start with oxygen. Are you wondering what the formula is? Chemists found a long time ago that two oxygen atoms join together to make an oxygen molecule, so what would the formula be? 9. Write the formula in the proper space. Then make the model. Remember to use the same color that you used above for oxygen. 10. Draw a picture of your model of the oxygen molecule on your data chart. 11. Label each atom or color it to show what kind they are. Remember to use the same color that you used above for oxygen. 12. Now try making a model of a hydrogen molecule. Like oxygen, two atoms of hydrogen join together to make a hydrogen molecule. 13. Write the formula in the proper space. 14. Draw a picture of your model of the hydrogen molecule on your data chart. 15. Label each atom or color it to show what kind they are. Remember to use the same color that you used above for hydrogen. Now that you know the formula and can make a model of each reactant and each product, you are ready to figure out how new substances form. Recall from the last lesson what makes one substance different from another: Each substance is made up of its own kind of molecule, made of different kinds of atoms. Water is a collection of water molecules, each molecule made from 2 hydrogen and 1 oxygen atoms. Vinegar is a collection of vinegar molecules, each molecule made from 2 carbon atoms, 4 hydrogen atoms, and 2 oxygen atoms. Sugar is made of sugar molecules, each molecule made from 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms. What happens when an electric current runs through water, and the water decomposes into hydrogen gas and oxygen gas? The atoms of the water molecules come apart and then form into new molecules. No new atoms of any kind are added. Its like taking a Lego building apart and using all the pieces to make two smaller objects, like a plane and a tree. 57

58 Let s try doing this with your models. Take a molecule of water apart and USE THESE SAME ATOMS to make the products, in this case, oxygen and hydrogen molecules. What happens? You can make the hydrogen molecule (H2), but you cannot make the oxygen molecule (O2), because you have only one oxygen atom. Where can the other oxygen atom come from to make an oxygen molecule? In the real chemical reaction you watched, with many bubbles being formed, there were billions and billions of molecules. Billions of water molecules were coming apart at the same time. And all the other water molecules coming apart also have an oxygen atom. So two oxygen atoms from different water molecules find each other and join together to form an oxygen molecule. Try doing that with your models now. 16. Take a second molecule of water apart and make another hydrogen molecule. 17. Use this single oxygen atom to join the oxygen atom from the first water molecule. Together they form an oxygen molecule. How many water molecules did you use in all? 18. Draw exactly that many water molecules in the space on your data sheet labeled PICTURES OF MODELS FOR THE REACTION. 19. Color your models using the same color code as above. How many hydrogen molecules were formed? 20. Draw exactly that many hydrogen molecules in the appropriate space on your data sheet. 21. Color your models using the same color code as above. 58

59 How many oxygen molecules were formed? 22. Draw exactly that many oxygen molecules in the appropriate space on your data sheet. 23. Color your models using the same color code as above. Are you beginning to see how atoms rearrange themselves to make new substances? Conservation of Matter Now let s see how atoms and molecules can be used to explain conservation of matter. Remember that conservation of matter in chemical reactions means that the beginning weight of all of the reactants is exactly the same as the ending weight of all of the products. Can you speculate about why this might be?????? 24. How many atoms of oxygen are there in the molecules of the reactant the starting substance? How many atoms of hydrogen are there in the molecules of the reactant? Record this information on your data sheet under ACCOUNTING FOR ATOMS. 25. How many oxygen atoms are there in the product molecules the ending substances? How many hydrogen atoms are there in the product molecules? Record this information on your data sheet in the appropriate space. WHAT DO YOU NOTICE ABOUT THE NUMBERS OF ATOMS IN THE STARTING SUBSTANCES AND THE ENDING SUBSTANCES? They are the same! The atoms don t disappear or appear out of nowhere they just rearrange themselves into new molecules. And if each atom has a certain weight (which it does), then how does the weight of the reactant compare with the weight of the products? This is the Law of Conservation of Matter, or the Law of Conservation of Mass. No weight is lost or gained in chemical reactions. No mass is lost or gained. No matter is lost or gained. Why? Because no atoms are lost or gained during chemical reactions. 59

60 Chemical Equations Chemists use a shorthand to write about this reaction. They show the starting substances on one side of an equation, and the ending substances on the other side, to show how their weights are equal. They use an arrow instead of an equal sign, to show that the left side reactants change into the right side products. The formula for this reaction is 2 H2O 2 H2 + O2 The 2 in front of the H2O means that two molecules of water were used in the reaction. The 2 in front of the H2 means that two molecules of hydrogen gas were formed. No number in front of the O2 means that one molecules of oxygen gas was formed. 26. Write the formula for this reaction on your chart. 60

61 Lesson 13: Atoms In, Atoms Out Decomposing Water Think & Write Questions 1. When water boils a gas leaves its surface, and the level of the water goes down. When water is chemically decomposed, like in this experiment, it forms gas and the level of the water also goes down. What s the difference between boiling and decomposing water? 2. Could chlorine gas, Cl2 be a product in this reaction? What about carbon dioxide CO2? Explain why you think this. 3. Do you think it would be possible for ozone, O3 to form as a product in this reaction? What about hydrogen peroxide, H202? Explain why you think this. 4. Explain the difference between the two number 2 s in the 2H20 model. Use your models to help you. 5. After doing this same experiment with water that you just completed, and doing it until all the water was gone, the teacher asked what happened to the water. Jamie responded quickly with, Oh, that s easy. It just decomposed into nothing. You are now an expert at this. How would you help Jamie understand what happened? 61

62 Lesson 14: Atoms In, Atoms Out Rusting Let s repeat the whole process now with a different chemical reaction: rusting. Take a minute or two to remember what a fresh piece of steel wool and a piece that has reacted (perhaps the one with the balloon on top) look like. Fe + O2 Fe2O3 1. You have a friend who doesn t know the first thing about chemistry. He thinks rust just starts somehow and then eats away at cars or pipes sort of like termites eat wood and this makes holes in the car or in the pipe. You must explain to him what is really going on. Tell him what the reactants are and where they come from. Explain what product is formed and how this happens. 62

63 2. Is rust just the same thing as iron, only brown? Explain. 3. A friend of yours says that she left a shovel outside during the winter and it got rusty. She says that if you scrape off the rust with a steel brush, the shovel will be as good as new. To test her knowledge of chemical reactions, you ask her if it will weight the same after the rust is scraped off as when she bought it. She says she s not sure but it seems like it should after all, rust just grows on the shovel like moss on a tree or mold on stale bread. Do you agree? Explain. Use atoms and molecules in your explanation. 4. Some cars and trucks get so rusty that holes start to form in the metal. How does this happen? 5. Give some examples of how we protect things made of iron and keep them from rusting. Then explain how the protection works. 63

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66 Balance these Equations!! Make sure to account for the atoms on both sides of the reaction. Remember, the atoms on the reactant side must equal the atoms on the product side. Fill in the blanks with the correct co-efficient! 1. 4Si + S8 2Si2S4 Si = Si = S = S = 2. P + 5O2 2P2O5 P = P = O = O = 3. Si + F2 SiF4 Si = Si = F = F = 4. C2H6 + 7O2 6H2O + 4CO2 C = C = H = H = O = O = 66

67 5. PCl5 + 4H2O H3PO4 + 5HCl P = P = Cl = Cl = H = H = O = O = 6. Ca + N2 Ca3N2 Ca = Ca = N = N = 7. SO3 + H2O H2SO4 S = S = O = O = H = H = 8. C6H4Cl2 + O2 6CO2 + H2O + Cl2 C = C = H = H = Cl = Cl = O = O = 67

68 9. 2C4H10O2 + O2 8CO2 + 10H2O C = C = H = H = O = O = 10. 3Ca + DyF3 Dy + 3CaF2 Ca = Ca = Dy = Dy = F = F = 68

69 Part Two: Density & Volume 69

70 Calculating Volume Lab In today s lab you will learn three different methods to calculate volume. Method 1 L x W x H Method 2 Overflow Method Method 3 - Displacement Station #1: You will be calculating volume using the L x W x H method. Record your data below. What is the volume of each object at that station? Object Description Volume Station #2: You will be calculating volume using the overflow method. Record your data below. What is the volume of each object at that station? Object Description Volume 70

71 Station #3: You will calculate volume using the displacement method. Record your data below. What is the volume of each object at that station? Object Description Volume Station #4: You will answer the following questions: 1. What makes up the mass of an object? 2. What does the term volume mean to you? 3. What makes one object more dense than another? 4. How can we change the density of an object? 5. If density changes, would you notice a change in mass and volume? 71

72 Identifying Substances Based on Their Densities PURPOSE: To identify substances based on their densities. PROCEDURE: 1. Select a block and write a brief physical description of it in the data table below. 2. Weigh the block and record its mass in the data table below. 3. Calculate its volume (L x W x H) and record the volume in the data table below. 4. Calculate the density using the following formula: Density = Mass in grams (g) Volume in cubic centimeters (cm 3 ) 5. Record the density of each block in the data table below. 6. Look at the table of known densities and decide the material from which each block is composed. 7. Repeat steps 1-6 for 4 remaining blocks. RESULTS/DATA Description Mass Volume Density Material grams cm 3 g/cm 3 grams cm 3 g/cm 3 grams cm 3 g/cm 3 grams cm 3 g/cm 3 grams cm 3 g/cm 3 grams cm 3 g/cm 3 grams cm 3 g/cm 3 grams cm 3 g/cm 3 grams cm 3 g/cm 3 grams cm 3 g/cm 3 Table of Known Densities: Material Actual Density (g/cm 3 ) Calculated Density Range Copper Brass Steel Aluminum Acrylic : Material Actual Density (g/cm 3 ) Calculated Density Range Oak Nylon Pine Rosewood Poplar PVC

73 1. How would you define density? CONCLUSION QUESTIONS: 2. Which material was the most dense? The least dense? 3. How were the most-dense substances physically different from the least dense substances? 73

74 Calculating the Density of Sand and Water Goal- To create an experiment that will allow you to calculate the density of sand and water. Materials- Sand Water 2 Beakers Scale Procedure- Determine the best way to calculate the density of sand and water based on the materials you have. List the steps to your procedure in the space provided. Procedure Data Table Mass (g) Volume (ml) Density (g/ml) Sand Water Conclusion- Analyze your data and write a conclusion for it here. Create a graph of your results. 74

75 Density / Mass / Volume Analysis: 1. What is density? 2. How do you calculate density? 3. What is the density of a piece of wood that has a mass of 25 grams and a volume of 5 cm 3? 4. How can we change the density of an object? 5. What happens to the density of a bar of soap if I cut the bar in half? 6. You observe two beakers of water that have the same volume. One contains very hot water and the other contains very cold water. Use this information to answer the following questions: a. What can be said about the mass of each beaker? b. What can be said about the volume of each beaker? c. What can be said about the density of each beaker? 75

76 Part Three: Periodic Table of the Elements 76

77 SECTION 1.1 ATOMS ARE THE SMALLEST FORM OF ELEMENTS. Reading Study Guide A BIG IDEA A substance s atomic structure determines its physical and chemical properties. KEY CONCEPT Atoms are the smallest form of elements. Vocabulary proton a positively charged particle within an atom neutron an uncharged particle within an atom nucleus protons and neutrons together at an atom s center electron a negatively charged particle moving around the outside of the nucleus atomic number the number of protons in the nucleus in an atom atomic mass number combined number of protons and neutrons in a nucleus isotope element that has the same number of protons, but a different number of neutrons from another atom of the same element ion an atom that has gained or lost electrons CHAPTER 1 Atomic Structure and the Periodic Table Review If the statement is true, write true. If it is false, replace the underlined word to make it true. Copyright by McDougal Littell, a division of Houghton Mifflin Company 1. Atoms are made of protons, neutrons, and isotopes.. 2. Each element has a unique atomic number.. Take Notes I. All matter is made of atoms. (p. 9) 3. About how many different elements make up everything on Earth? A B. Types of Atoms, Names and Symbols of Elements (p. 10) 4. All living things contain some common elements. Their symbols are given below. Write the name of each element next to its symbol. O C N H Which one of these is the most common element in the universe? CHEMICAL INTERACTIONS, CHAPTER 1, READING STUDY GUIDE A 13 77

78 CHAPTER 1 Atomic Structure and the Periodic Table II. Each element is made of a different atom (p. 11) A B. The Structure of an Atom, Atomic and Atomic Mass Numbers (pp ) 5. What are the three particles that make up an atom? 6. What is the atomic number of an atom? 7. Atomic mass number is the sum of and. What is an isotope? III. Atoms form ions. (p. 14) 8. An ion is an atom that has a positive or negative charge. What happens when an atom becomes an ion? A B. Formation of Positive Ions and Formation of Negative Ions (pp ) 9. All aluminum atoms have 13 protons. Aluminum atoms often lose 3 electrons to form ions. Label the ion on the right side by noting the protons and electrons that remain. 13 electrons (13 ) 13 aluminum atom (Al) Loses 3 electrons Copyright by McDougal Littell, a division of Houghton Mifflin Company 14 CHEMICAL INTERACTIONS, CHAPTER 1, READING STUDY GUIDE A 78

79 CHAPTER 1 Atomic Structure and the Periodic Table SECTION 1.2 ATOMS OF ELEMENTS MAKE UP THE PERIODIC TABLE. Reading Study Guide A BIG IDEA A substance s atomic structure determines its physical and chemical properties. KEY CONCEPT Atoms of elements make up the periodic table. Vocabulary atomic mass average mass of all the element s isotopes periodic table the table that shows the repeating pattern of properties of the elements group the elements in a column of the periodic table period a horizontal row in the periodic table Review 1. Fill in the concept map for atoms. are made of ATOMS Take Notes have a central which contains around which orbit I. Elements can be organized by similarities. (p. 17) 2. The average mass of all an element s isotopes is its. Copyright by McDougal Littell, a division of Houghton Mifflin Company 24 CHEMICAL INTERACTIONS, CHAPTER 1, READING STUDY GUIDE A 79

80 A. Mendeleev s Periodic Table and Predicting New Elements (pp ) 3. Fill in the main-idea web for the main idea shown. The elements in rows had similar. A periodic table shows Mendeleev produced the first periodic table.. CHAPTER 1 Atomic Structure and the Periodic Table II. The periodic table organizes the atoms of the elements by properties and atomic number. (p. 19) 4. How is the modern periodic table organized? A. Reading the Periodic Table (p. 19) 5. One square from the periodic table is shown below. Label each of the parts of this element s square. Copyright by McDougal Littell, a division of Houghton Mifflin Company A B C D 37 Rb Rubidium How many protons does the element shown above have? B. Groups and Periods (p. 22) 7. What are the vertical columns of the periodic table called? 8. What is the horizontal row called? C. Trends in the Periodic Table (pp ) A B C D 9. How does atomic size change as you move down the periodic table? CHEMICAL INTERACTIONS, CHAPTER 1, READING STUDY GUIDE A 25 80

81 A1 Building Atoms What is an atom? Atoms make up everything you see, touch, smell, and eat. Atoms are so small you can8t see them. It takes millions and millions of atoms to form a single crystal of salt in your salt shaker. Each type of atom is called an element. All the elements are represented on a special chart called the periodic table. In this investigation, you will use the Atom Building Game to learn the parts of an atom and what makes the atoms of one element different from the atoms of another element. A What are the parts of an atom? The Atom Building Game represents a model of an atom. The center of the board represents the nucleus of an atom. The outer rings around the center represent energy levels. Three colors of marbles come with the game. The marbles represent the three kinds of subatomic particles in the atom. The green marbles represent protons. The blue marbles represent neutrons. Protons and neutrons always go in the nucleus of an atom. The yellow marbles represent electrons. Electrons always go in the energy levels. Investigation A1 Materials Protons and electrons have charge. Charge can be positive or negative. Each proton has a positive charge of +1. Each electron has a negative charge of G1. Neutrons have no charge and are Ineutral.J When the number of protons equals the number of electrons in an atom, the atom has no charge. An atom has a charge when the number of protons is different from the number of electrons. An atom with a positive or negative charge is called an ion. As you answer the questions, you will build a beryllium atom. When asked to find the total charge for a group of subatomic particles, use the following formula: Number of particles Charge of one particle = Total charge! One Atom Building Game with marbles.! Periodic table that comes with the game a. Place four protons (green marbles) in the center of the board. What is the total charge of the protons? b. Place five neutrons (blue marbles) in the center of the board with the protons. What is the total charge of the protons plus the neutrons? Atom Building Game Copyright 2009 CPO Science Can be duplicated for classroom use 1 81

82 c. If you have four electrons (yellow marbles), what is the total charge of these particles? d. Finish building the atom, by adding the four electrons to the outer levels on the board. Now, add the total charges of all the particles in the atom. What is the total charge of the atom you built? e. Draw a diagram of the beryllium atom. Include all the parts of the atom. Label your diagram. 2 Copyright 2009 CPO Science Can be duplicated for classroom use 82

83 B Identifying elements Investigation A1 On the Atom Building Game board, you have a model of a beryllium atom. This atom has four protons, five neutrons, and four electrons. You can find out more information about beryllium by looking at the periodic table that comes with the Atom Building Game. a. What is the symbol for the element beryllium? b. What is the atomic number for beryllium? The atomic number of an element is equal to the number of protons in the nucleus of an atom of the element. Since the atomic number of beryllium is 4, all beryllium atoms have 4 protons. Fill in the Element Name and Atomic Number columns in the table below. Element Name Atomic Number Number of protons Number of electrons Mass number Number of neutrons Hydrogen 1 Oxygen Calcium C Building atoms 1. Use the atomic numbers for the elements to fill in the Number of protons column in the table above. 2. The number of electrons in an atom equals the number of protons. Use this information to fill in the Number of electrons column in table above. Atom Building Game Copyright 2009 CPO Science Can be duplicated for classroom use 3 83

84 D 3. The mass number for an atom is equal to the number of protons and neutrons in the nucleus. Atoms of an element can have different numbers of neutrons, but all atoms of an element have the same number of protons. The formula for mass number is: Number of protons 4. Rearrange the formula for mass number so that it is a formula for figuring out the number of neutrons in an atom. Use this new formula and the mass numbers in the table above to fill in the Number of neutrons column. What are isotopes? + Number of neutrons = Mass number Atoms of the same element that have different mass numbers are called isotopes. Hydrogen has two isotopes. One has a mass number of I1K and is called hydrogen-1. The other has a mass number of I2K and is called hydrogen-2. a. How many neutrons does hydrogen-1 have? How many neutrons does hydrogen-2 have? b. How many isotopes does magnesium have? Write the names of these isotopes. c. How many neutrons does an atom of copper-65 have? How many protons does it have? 4 Copyright 2009 CPO Science Can be duplicated for classroom use 84

85 Assessment Investigation A1 1. Use the periodic table to fill the Atomic number and Number of protons columns for each atom in the table. Use the numbers of protons and electrons to fill in the Total charge column. Then decide whether each atom is an ion. Element name Atomic number Number of protons Number of electrons Total charge Is the atom an ion? hydrogen 0 lithium 2 beryllium 4 boron 2 oxygen 8 fluorine The first two columns of the table below are partially filled in. Use the periodic table to help you fill in the other columns. Then fill in the Number of protons and Number of electrons. Use the mass number and number of protons to fill in the Number of neutrons column for each atom. Element name Atomic number Number of protons Number of electrons Mass number Number of neutrons hydrogen oxygen silicon 28 phosphorus xenon 124 Atom Building Game Copyright 2009 CPO Science Can be duplicated for classroom use 5 85

86 Extra space for notes: 6 Copyright 2009 CPO Science Can be duplicated for classroom use 86

87 A2 Atomic Challenge What holds and atom together? An atom(s structure includes a nucleus with protons and neutrons, and energy levels with electrons. Each of the protons has a positive charge. Each of the electrons has a negative charge. Positive charges and negative charges attract one another. The attractive atomic force between charges helps hold an atom together. In this investigation, you will learn more about the forces that hold an atom together. You will use your understanding of atomic structure to play a game called the Atomic Challenge. A What holds an atom together? Investigation A2 One of the atomic forces that holds an atom together is called electromagnetic force. This force follows certain rules. The rules are explained below and illustrated in the diagram. The rules for electromagnetic force are: A A A Positive charges attract negative charges. Positive charges repel other positive charges. Negative charges repel other negative charges. Electromagnetic force is responsible for holding the electrons in place. The electrons are attracted to the protons in the nucleus of the atom. Materials! One Atom Building Game with marbles.! Periodic table that comes with the game a. Using the Atom Building Game, build a helium atom using two protons (green marbles), two neutrons (blue marbles), and two electrons (yellow marbles). Place the green and blue marbles close together in the nucleus of the board. Place the electrons in the first energy level (the nearest one to the nucleus). What is the total charge of the subatomic particles in the nucleus of this atom? b. According to the rules for electromagnetic force, what should happen to these two protons in the nucleus when they are close together? Atom Building Game Copyright 2009 CPO Science Can be duplicated for classroom use 1 87

88 B What keeps the nucleus from flying apart? Another atomic force that holds an atom together is called strong nuclear force. Strong nuclear force holds the positively charged nucleus together. This force only works when the subatomic particles are very close together. If the particles are too far apart, electromagnetic force takes over and causes the particles to repel each other. Here are the rules for strong nuclear force: F F F Strong nuclear force holds protons and protons together when they are very close. Strong nuclear force holds neutrons and neutrons together when they are very close. Strong nuclear force holds protons and neutrons together when they are very close. a. In the diagram below, why do you think there are more arrows representing strong nuclear force than there are representing electromagnetic force? b. In your own words, describe how electromagnetic and strong nuclear forces hold an atom together. C Introduction to the Atomic Challenge Game Atomic Challenge is a game that you will play using the Atom Building Game. To play this game you need to understand the information on the periodic table. Take some time now to go over the periodic table in your group. Work together until everyone understands the difference between the atomic number and the mass number for an atom, and the difference between an ion and an isotope. Two more terms that you will need to understand are stable and neutral. The mass numbers of all stable isotopes of the elements are listed on the periodic table. Neutral atoms have equal numbers of protons and electrons. 2 Copyright 2009 CPO Science Can be duplicated for classroom use 88

89 Investigation A2 For each of these terms, write a sentence that shows you understand its definition. a. atomic number b. mass number c. ion d. isotope e. stable f. neutral Atom Building Game Copyright 2009 CPO Science Can be duplicated for classroom use 3 89

90 D E Setting up 1. Each Atom Building Game board can have four players. Each player should use one of the four pockets at the corners. 2. Each player should start with the following marbles in their pocket: 6 blue marbles (neutrons) 5 green marbles (protons) 5 yellow marbles (electrons) 3. The remaining marbles stay in the containers and are the Lbank.M Players may need to trade marbles with the bank later in the game. The game of Atomic Challenge The object of the game is to play all your marbles by adding them to the board to make neutral, stable atoms. The first player to run out of marbles wins. After each turn, you must identify the atom you made. For example, after a play you might say Llithium sixm if the marbles you added made an atom with 3 protons (green marbles), 3 neutrons (blue marbles), and 3 electrons (yellow marbles). Each player takes turns adding up to 5 marbles to the atom. Marbles must be added according to these rules for building atoms: 1. The number of protons matches the atomic number of the atom. Number of green marbles = Atomic number 2. The total number of protons and neutrons equals one of the mass numbers for that element. Green marbles + Blue marbles = Mass number 3. The number of electrons and protons match. Number of yellow marbles = Number of green marbles 4. Protons and neutrons go in the nucleus. Only green and blue marbles in the center of the board. 5. Electrons go in the energy levels. Only yellow marbles in the energy levels. Example move: In the graphic above, lithium-7, with 3 protons, 4 neutrons, and 3 electrons, is represented on the Atom Building Game board. If 1 proton (green marble), 1 blue marble (neutron), and 1 electron (yellow marble) are added, the atom becomes beryllium-9. Beryllium has 4 protons, 5 neutrons, and 4 electrons. 4 Copyright 2009 CPO Science Can be duplicated for classroom use 90

91 F Additional rules Investigation A2 1. You can add no more than 5 marbles per turn. The 5 marbles can include any mix of colors, such as 2 green, 1 blue, and 2 yellow. You may not always be able to add 5 marbles; sometimes you will only be able to add 3 or 4 and still make a real atom. 2. You can challenge a move. After each playeris turn, look at the periodic table that comes with the Atom Building Game to see whether the atom is correct or not. If the atom has been incorrectly built or identified, you can challenge the move. A player that makes an atom incorrectly during his or her turn must take the marbles back and does not get to try again until the next turn. The next player then takes a turn. 3. A player can trade marbles with the bank INSTEAD of taking his or her turn. You can take as many marbles, and of as many colors, as you need, but you must take at least as many total marbles as you put in. For example you can trade 2 yellows for 1 yellow, 1 blue, and 1 green. You can put in 2 and take 3, but you cannot put in 2 and take only 1 back. After you have completed a game of Atomic Challenge, answer the following questions. G What did you learn? a. What atomic force keeps electrons in place around the nucleus of an atom? b. What atomic force holds the nucleus of an atom together? Why is this force necessary? c. What is the atomic number of sodium? d. How many protons does sodium have? e. How many isotopes does calcium have? Atom Building Game Copyright 2009 CPO Science Can be duplicated for classroom use 5 91

92 f. What is the mass number of beryllium? g. What is the charge on a bromine atom that has 35 protons and 36 electrons? h. What do you call an atom that has a positive or a negative charge? i. What does it mean when an atom is stable and neutral? j. The Atom Building Game is a model of an atom. In your own words, define the term Jmodel.K Include in your answer why models are useful. k. Describe three ways in which the Atom Building Game is like a real atom and three ways it is not. 6 Copyright 2009 CPO Science Can be duplicated for classroom use 92

93 Investigation A2 Assessment 1. An Atom Building Game has 16 green marbles, 16 blue marbles, and 18 yellow marbles. Answer the following questions based on this information. a. What atom is represented on the Atom Building Game board? b. What is the total charge of this atom? c. What would you need to do to make this atom neutral? 2. Atoms of an element can have more than one mass number, but only one atomic number. Why? 3. What is the difference between a stable atom and a neutral atom? Can an atom be both stable and neutral? 4. Why is the periodic table of the elements an important tool in science? Come up with as many reasons as you can to explain why the periodic table is so useful. Atom Building Game Copyright 2009 CPO Science Can be duplicated for classroom use 7 93

94 Extra space for notes: 8 Copyright 2009 CPO Science Can be duplicated for classroom use 94

95 A3 Building Molecules What is a molecule? When atoms combine with other atoms, they form molecules. The number of electrons in the outermost energy level is important to understanding why atoms, like hydrogen and oxygen, combine to form molecules. Hydrogen and oxygen atoms combine to form water molecules. A What is a compound? Investigation A3 Materials you use can be either elements or compounds. Elements are made of only one kind of atom. Gold is an example of an element. A piece of pure gold contains billions of gold atoms and no other types of atoms. Compounds are made of two or more kinds of atoms. Table salt an example of a compound. The smallest particle of salt that exists is called a molecule. Each grain of salt in your salt shaker contains billions of salt molecules. Each salt molecule contains one sodium (Na) atom and one chlorine (Cl) atom. Another name for table salt is sodium chloride, which can be abbreviated NaCl. Use the above information to complete the table below. Materials! One Atom Building Game with marbles.! Periodic table that comes with the game Common name of material What atoms are in the material? Is the material an element or a compound? salt sodium (Na) and chlorine (Cl) compound diamond carbon (C) silver silver (Ag) sugar carbon (C), hydrogen (H), oxygen (O) iron iron (Fe) rust iron (Fe) and oxygen (O) Atom Building Game Copyright 2009 CPO Science Can be duplicated for classroom use 1 95

96 B Outermost energy levels The reason atoms combine with other atoms to make compounds has to do with the electrons in the outermost energy level. The outermost energy level is the one farthest from the nucleus of the atom. Use the Atom Building Game to build a neon- 20 atom. When you add electrons (yellow marbles) to an atom, fill the energy level closest to the nucleus first before filling the next energy level. a. How many electrons are in the outermost energy level of your neon-20 atom? b. Are there any empty spaces in the outermost energy level of the neon-20 atom? c. Do you think a neon atom would combine with another atom to form a compound? Why or why not? C Combining atoms For this part of the investigation, your group will pair up with another group in your class. When you have paired up, decide which group will build a sodium-23 atom and which will build a chlorine-35 atom. After you have built these atoms, place them close together and answer the questions below. 2 Copyright 2009 CPO Science Can be duplicated for classroom use 96

97 Investigation A3 a. How many electrons does sodium have in its outermost level? How many empty spaces does it have in its outermost level? b. How many electrons does chlorine have in its outermost level? How many empty spaces does it have in its outermost level? c. Sodium and chlorine combine to form a compound known as sodium chloride. You know this compound as Ctable salt.d Why do you think these two atoms tend to combine with each other? D What is a chemical bond? When two atoms combine their electrons to fill the outermost energy level, we say that they have formed a chemical bond. A group of atoms connected by bonds is called a molecule. In part 3, you made a molecule with only two atoms. Molecules can also be made of more than two atoms. For the next exercise, you will need to work with other groups in your class to make a water molecule using Atom Building Game boards. Water molecules contain one oxygen atom and some hydrogen atoms. a. Make oxygen-16 with your Atom Building Game board. How many hydrogen atoms will you need to complete the outermost energy level of the oxygen? b. Once you have figured out how many hydrogen atoms you need, get together with the same number of groups in your class. With the other groups, place the boards together to make the water molecule. Atom Building Game Copyright 2009 CPO Science Can be duplicated for classroom use 3 97

98 c. Do you think water is an element or a compound? Explain your answer. d. Complete the chemical formula for water (see diagram to the right). Write the number of hydrogen atoms in a water molecule in the blank next to the symbol for hydrogen (H). e. What does a chemical formula tell you about a compound? f. In the case of the neon-20 atom, the molecule of sodium chloride, and the molecule of water, how many electrons, in total, were in the outermost energy levels? Why do you think atoms combine with other atoms? 4 Copyright 2009 CPO Science Can be duplicated for classroom use 98

99 Investigation A3 Assessment 1. Explain the difference between an element and a compound. Give one example of each. 2. Sodium and chlorine combine to form a molecule of table salt. a. Why are sodium and chlorine a good match for making a molecule? b. Fluorine has the same number of electrons in its outermost energy level as sodium. How many sodium atoms do you think will combine with fluorine? Explain your reasoning. 3. Which one of the three different subatomic particles in an atom is involved in forming bonds between atoms? Why do you think the other two kinds of subatomic particles are not involved in forming bonds? 4. Look at the periodic table. The last column (group 18) contains a group of elements called the Mnoble gases.n The atoms of these elements do not combine with other atoms to form compounds. a. How many electrons do you think atoms of the noble gases have in their outermost energy levels? b. Explain why noble gases do not combine with other atoms to make compounds. Atom Building Game Copyright 2009 CPO Science Can be duplicated for classroom use 5 99

100 Extra space for notes: 6 Copyright 2009 CPO Science Can be duplicated for classroom use 100

101 CHAPTER 1 Atomic Structure and the Periodic Table SECTION 1.3 THE PERIODIC TABLE IS A MAP OF THE ELEMENTS. Reading Study Guide A BIG IDEA A substance s atomic structure determines its physical and chemical properties. KEY CONCEPT The periodic table is a map of the elements. Vocabulary reactive how likely an element is to undergo a chemical change metals elements that conduct electricity, are shiny, and heat well nonmetals elements with properties the opposite of metals metalloids elements with properties between metals and nonmetals radioactivity the process where atoms release particles and produce energy half-life the amount of time it takes for half of the atoms in a set amount of a substance to decay Review 1. Look at this column from the periodic table below. What properties are most likely similar among these elements? Explain why Co Cobalt Rh Rhodium Ir Iridium Mt Meitnerium (268) Take Notes I. The periodic table has distinct regions. (p. 26) 2. The periodic table is divided into three regions nonmetals, metals, and metalloids. Label these regions on the diagram below Copyright by McDougal Littell, a division of Houghton Mifflin Company CHEMICAL INTERACTIONS, CHAPTER 1, READING STUDY GUIDE A 101

102 3. Some elements are more reactive than others. Which groups on the periodic contains the elements that are most reactive? II. Most elements are metals. (p. 27) 4. Name four characteristics of metals. A B. Reactive Metals, Transition Metals, and Rare Earth Elements (pp ) 5. Why are sodium and potassium often stored in oil? CHAPTER 1 Atomic Structure and the Periodic Table 6. Name two uses for transition metals. III. Nonmetals and metalloids have a wide range of properties. (p. 29) 7. List three examples of nonmetals. 8. What is a common use for metalloids? Copyright by McDougal Littell, a division of Houghton Mifflin Company IV. Some atoms can change their identity. (p. 30) 9. Fill in the main-idea web for the main idea shown. An element's identity depends on the number of protons it has. The stability of the nucleus. Some atoms can change their identity. Radioactivity is a process where. An isotope is radioactive if. A B. Uses of Radioactivity in Medicine and Radioactive Decay (pp ) 10. What is one way radioactivity is used in medicine? CHEMICAL INTERACTIONS, CHAPTER 1, READING STUDY GUIDE A

103 H hydrogen [1.007; 1.009] 3 Li lithium [6.938; 6.997] 4 Be beryllium atomic number Symbol name standard atomic weight IUPAC Periodic Table of the Elements 2 Key: B boron [10.80; 10.83] 6 C carbon [12.00; 12.02] 7 N nitrogen [14.00; 14.01] 8 O oxygen [15.99; 16.00] 9 F fluorine He helium Ne neon Na sodium Mg magnesium Al aluminium Si silicon [28.08; 28.09] 15 P phosphorus S sulfur [32.05; 32.08] 17 Cl chlorine [35.44; 35.46] 18 Ar argon K potassium Rb rubidium Cs caesium Fr francium 20 Ca calcium Sr strontium Ba barium Ra radium 21 Sc scandium Y yttrium lanthanoids actinoids 22 Ti titanium Zr zirconium Hf hafnium Rf rutherfordium 23 V vanadium Nb niobium Ta tantalum Db dubnium 24 Cr chromium Mo molybdenum 95.96(2) 74 W tungsten Sg seaborgium 25 Mn manganese Tc technetium 75 Re rhenium Bh bohrium 26 Fe iron Ru ruthenium Os osmium Hs hassium 27 Co cobalt Rh rhodium Ir iridium Mt meitnerium 28 Ni nickel Pd palladium Pt platinum Ds darmstadtium 29 Cu copper Ag silver Au gold Rg roentgenium 30 Zn zinc 65.38(2) 48 Cd cadmium Hg mercury Cn copernicium 31 Ga gallium In indium Tl thallium [204.3; 204.4] 32 Ge germanium Sn tin Pb lead Fl flerovium 33 As arsenic Sb antimony Bi bismuth Se selenium 78.96(3) 52 Te tellurium Po polonium 116 Lv livermorium 35 Br bromine I iodine At astatine 36 Kr krypton Xe xenon Rn radon 57 La lanthanum Ce cerium Pr praseodymium Nd neodymium Pm promethium 62 Sm samarium Eu europium Gd gadolinium Tb terbium Dy dysprosium Ho holmium Er erbium Tm thulium Yb ytterbium Lu lutetium Ac actinium 90 Th thorium Pa protactinium U uranium Np neptunium 94 Pu plutonium 95 Am americium 96 Cm curium 97 Bk berkelium 98 Cf californium 99 Es einsteinium 100 Fm fermium 101 Md mendelevium 102 No nobelium 103 Lr lawrencium Notes - IUPAC 2009 Standard atomic weights abridged to four significant digits (Table 4 published in Pure Appl. Chem. 83, (2011); doi: /pac-rep ). The uncertainty in the last digit of the standard atomic weight value is listed in parentheses following the value. In the absence of parentheses, the uncertainty is one in that last digit. An interval in square brackets provides the lower and upper bounds of the standard atomic weight for that element. No values are listed for elements which lack isotopes with a characteristic isotopic abundance in natural terrestrial samples. See PAC for more details. INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY - Aluminum and cesium are commonly used alternative spellings for aluminium and caesium. - Claims for the discovery of all the remaining elements in the last row of the Table, namely elements with atomic numbers 113, 115, 117 and 118, and for which no assignments have yet been made, are being considered by a IUPAC and IUPAP Joint Working Party. For updates to this table, see iupac.org/reports/periodic_table/. This version is dated 1 June Copyright 2012 IUPAC, the International Union of Pure and Applied Chemistry. 103

104 Using the Periodic Table Element Name Hydrogen Symbol Ag Atomic # 86 Atomic Mass Group # 1 Period # 3 Family Name Alkali Metals # of Protons 92 # of Electrons # of Neutrons Solid, Liquid, Gas Metal, Nonmetal or Metalloid 104

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