Chemistry Matter of Change

Chapters 1–4 Resources

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Copyright © by The McGraw-Hill Companies, Inc. All rights reserved. Permission is granted to reproduce the material contained herein on the condition that such materials be reproduced only for classroom use; be provided to students, teachers, and families without charge; and be used solely in conjunction with the Glencoe Chemistry: Matter and Change program. Any other reproduction, for sale or other use, is expressly prohibited. Send all inquiries to: Glencoe/McGraw-Hill 8787 Orion Place Columbus, OH 43240-4027































Table of Contents To the Teacher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv

Chapters 1-4 Resources Reproducible Student Pages Student Lab Safety Form . . . . . . . . . . . . . . . . . . . . . . . . . . vi Chapter 1 Introduction to Chemistry . . . . . . . . . . . . . . . . . . . . . . . . 1 Chapter 2 Analyzing Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Chapter 3 Matter—Properties and Changes . . . . . . . . . . . . . . . . . . . . 51 Chapter 4 The Structure of the Atom . . . . . . . . . . . . . . . . . . . . . . . . 81 . c n I , s e i n a p m o C l l i H w a r G c M e h T f o n o i s i v i d a , l l i H w a r G c M / e o c n e l G © t h g i r y p

Teacher Guide and Answers Chapter 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 Chapter 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 Chapter 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 Chapter 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123































To the Teacher This booklet contains resource materials to help you teach more effectively. You will find the following in the chapters:

Reproducible Pages Hands-on Activities MiniLab and ChemLab Worksheets: Each activity in this book is an expanded version of each lab that appears in the Student Edition of Glencoe Chemistry: Matter and Change. All materials lists, procedures, and questions are repeated so that students can read and complete a lab in most cases without having a textbook on the lab table. All lab questions are reprinted with lines on which students can write their answers. In addition, for student safety, all appropriate safety symbols and a nd caution statements have been reproduced reprodu ced on these expanded expa nded pages. Answer pages for each MiniLab MiniLa b and ChemLab are included in the Teacher Guide and Answers section at the back of this book.

Transparency Tr ansparency Activities Teaching Transparency Masters and Worksheets: These transparencies relate to major concepts that will benefit from an extra visual learning aid. Most of the transparencies contain art or photos that extend the concepts put forth in the textbook. Others contain art or photos directly from the t he Student Edition. There are 73 Teaching Transparencies, provided here as black-and-white black-and-white masters accompanied by worksheets that review rev iew the concepts presented in the tra nsparencies. Answers to worksheet questions are provided in the Teacher Guide and Answers section at the back of this book. Math Skills Transparency Masters and Worksheets: These transparencies relate to mathematical concepts that will benefit from an extra visual learning aid. Most of the transparencies contain art or photos directly from the Student Edition, or extend concepts put forth in the textbook. There are 42 Math Skills Transparencies, provided here as black-and-white blackand-white masters accompanied by worksheets that t hat review the t he concepts presented in the transparencies. tra nsparencies. Answers to worksheet questions are provided provided in the t he Teacher Guide and Answers section at the back of this book.

Intervention and Assessment Study Guide: These pages help students understand, organize, and compare the main chemistry concepts in the textbook. The questions and activities also help build strong study and reading skills. There are six study guide pages for each chapter. Students will find these pages easy to follow because the section titles match those in the textbook.

. c n I , s e i n a p m o C l l i H w a r G c M e h T f o n o i s i v i d a , l l i H w a r G c M / e o c n e l G © t h g i r y p































To the Teacher

continued

Chapter Assessment: Each chapter assessment includes several sections that assess students’ understandings at different levels.

• The Reviewing Vocabulary section tests students’ knowledge of the chapter’s chapter’s vocabulary. A variety of formats are used, including matching, true/false, completion, and comparison of terms. • The Understanding Main Ideas section consists of two parts: Part A tests recall and basic understanding of facts presented in the chapter, chapter, while Part B is designed to be more challenging and requires deeper comprehension of concepts than does Part A. Students may be asked to explain chemical processes and relationships or to make comparisons and generalizations. • The Thinking Critically section requires students to use several different higher-order learning skills, such as interpreting data and discovering relationships in graphs and tables, as well as a s applying their understanding understa nding of concepts to solve problems, problems, compare and contrast situations, and to make inferences or predictions. • The Applying Scientific Methods section puts students into the role of researcher. researcher. They may be asked to read about an experiment, simulation, or model and then apply their understanding of chapter concepts and scientific methods to analyze and explain the procedure and results. Many of the questions in this thi s section are open-ended, giving givi ng students the opportunity to demonstrate both reasoning and a nd creative problem-solvproblem-solving skills. Answers or possible responses to all questions are provided in the t he Teacher Guide and Answers section at the back of this book. . c n I , s e i n a p m o C l l i H w a r G c M e h T f o n o i s i v i d a , l l i H w a r G c M / e o c n e l G © t h g i r y p

STP Recording Sheet: Recording Sheets allow students to use the Standardized Test Practice questions in the Student Edition as a practice for standardized tests. STP Recording Sheets give them the opportunity to use bubble answer grids and numbers grids for recording answers. Answers for the STP Recording Sheets can be found in the Teacher Wraparound Edition on Standardized Test Practice pages. Teacher Guide and Answers: Answers or possible answers for questions in this booklet can be found in the Teacher Guide and Answers section. Materials, teaching strategies, and a nd content content background, along with chapter references, are also provided where appropriate.































Teacher Approval Initials Date of Approval

Lab Safety Form Name: Date: Lab type (circle one) : Launch Lab MiniLab ChemLab Lab Title: Read carefully the entire lab and then answer the following questions. Your teacher must initial this form before you begin the lab. l ab.

1. What is the purpose of the investigation?

2. Will you be working with a partner or on a team? design-your-o your-own wn procedure? Circle: 3. Is this a design-

Yes

No

t hat you must follow as you perform 4. Describe the safety procedures and additional warnings that this investiga i nvestigation. tion.

5. Are there any steps in the procedure or lab safety symbols that you do not understand? Explain.

. c n I , s e i n a p m o C l l i H w a r G c M e h T f o n o i s i v i d a , l l i H w a r G c M / e o c n e l G © t h g i r y p

































Table of Contents

Reproducible Pages

Chapter 1 Introduction to Chemistry MiniLab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ChemLab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Teaching Transparency Masters and Worksheets . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Study Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Chapter Assessment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 STP Recording Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

. c n I , s e i n a p m o C l l i H w a r G c































Name

Date

Class

mini LAB 1

Developing Observation Skills Observing and Inferring A chemist’s ability to make careful and accurate observations is developed early. The observations often are used to make inferences. An inference is an explanation or interpretation of observations.

Materials petri dish (2), graduated cylinder, cylinder, whole milk, water, water, vegetable oil, four different food colorings, toothpick (2), dishwashing detergent

Procedure 1. Read and complete the lab safety form. 2. Add water to a petri dish to a height of 0.5 cm. Add 1 mL of vegetable oil. 3. Dip the end of a toothpick in liquid dishwashing detergent. 4. Touch the tip of the toothpick to the water at the center of the petri dish. Record your detailed observations. 5. Add whole milk to a second petri dish to a height of 0.5 cm. 6. Place one drop each of four different food colorings in four different locations on the surface of the milk. Do not put a drop of food coloring in the center. 7. Repeat steps 3 and 4.

Analysis 1. De Desc scri ribe be what you observed in step 4.

2. De Desc scri ribe be what you observed in step 7.

3 Infer Oil, the fat in milk, and grease belong to a class of substances called lipids. What

. c n I , s e i n a p m o C l l i H w a r G c M































Name

CHEMLAB

Date

Class

1

Identify the Water Source he contents of tap water vary among communities. In some areas, the water is hard. Hard water is water that contains large amounts of calcium or magnesium ions. Hardness can be measured in milligrams per liter (mg/L) of calcium or magnesium ions. Hard water makes it difficult to get hair hair,, clothes, and dishes clean. In this lab, you will learn how hard water is softened and how softening water affects its ability to clean. You will also collect, test, and classify local sources of water.

T

Problem

Objectives

Materials

How can hard water be softened? How do hard and soft water differ in their ability to clean?

• Compare the effect of distilled water, hard water, and soft water on the production of suds. • Calculate the hardness of a water sample.

3 large test tubes with stoppers test-tube rack grease pencil 25-mL graduated cylinder distilled water dropper

hard water 250-mL beaker dish detergent metric ruler

Safety Precautions • Alway Alwayss wear safety safety goggles goggles and a lab apron. apron. • Was Washing hing soda soda is a skin and and eye irritant. irritant. . c n I , s e i n a p m o C l l i H w a r G c M

Pre-Lab 1. 2.

Read the entire CHEMLAB. Hypothesize about the effect hard and soft water will have on the ability of a detergent to

4.

Are there any other safety precautions you need to consider?































Name

Date

CHEMLAB

6.

1

The American Society of Agricultural Engineers, the U.S. Department of the Interior, and the Water Water Quality Association Association agree on the following classification of water hardness. GPG stands for grains per gallon. One GPG equals 17.1 mg/L. If a sample of water has 150 mg/L of magnesium ions, ions, what is its hardness in grains per gallon?

5.

Obtain about 50-mL of water sample 1 in a beaker from your teacher. Slowly pour the water sample into Test Tube 1 until you reach the marked height.

6.

Obtain about 50-mL of water Sample 2 in a beaker from your teacher. Slowly pour water Sample 2 into Test Tube 2 until you reach the marked height.

7.

Add one drop of dish detergent to each test tube. Stopper the tubes tightly. Then shake each sample for 30s to produce suds. Use a metric ruler to measure the height of the suds.

Classification of Water Hardness Classification Soft Moderate Hard Very hard

mg/L

GPG

0–60

0–3.5

61–120

3.5–7

121–180

7–10.5



180



Cleanup and Disposal 1.

10.5 2.

Procedure 1. 2.

3.

4.

Class

Use some of the soapy solutions to remove the grease marks from the test tubes. Rinse all of the liquids down the drain with lots of tap water. Return all lab equipment to its designated location.

Read and complete the lab Safety form. Use a grease pencil to label three large test tubes D (for distilled water), 1 (for Sample 1), and 2 (for Sample 2).

Production of Suds Sample

Use a 25-mL graduated cylinder cylinder to measure out 20-mL of distilled water. water. Pour the water into Test Test Tube D. Stopper the tube.

Distilled water

Place Test Tube 1 next to Test Tube 2 and make a mark on Test Tube H that corresponds to the height of the water in Test Tube D.

Sample 2

Sample 1

Level of Suds (cm) . c n I , s e i n a p m o C l l i H w a r G c M































Name

CHEMLAB

3.

Date

Class

1

Calculate If the 50 mL of hard water that you obtained obtained contained 7.3 mg of magnesium, magnesium, how hard would the water water be according to the table below below (50 mL = 0.05 L)?

Classification of Water Hardness Classification Soft

0–60

Moderate

61–120

Hard

121–180

Very hard


mg of Calcium or Magnesium /L

>180

4.

Apply Scientific Methods Identify the independent and dependent variables in this lab. Was there a control in this lab? Explain. Did all your classmates have the same results as you? Why or why not?

5.

Error Analysis Could the procedure be changed to make the results more quantitative? Explain.

Inquiry Extension Investigate There are a number of products that claim to soften water. Visit a grocery

































Name

Date

TEACHING TRANSPARENCY MASTER

Earth’s Atmosphere

Class

1 Use with Chapter 1, Section 1.1

Exosphere 500 Thermosphere 100 ) m k ( e 75 d u t i t l A 50

Stratosphere

25

Troposphere

Mesosphere































Name

Date

TEACHING TRANSPARENCY WORKSHEET

Earth’s Atmosphere 1. In which layer of Earth’s atmosphere do commercial airplanes fly?

2. In which layer of Earth’s atmosphere would you find the peaks of mountains?

3. In which layer of Earth’s atmosphere would you find the ozone layer?

4. In which layer of Earth’s atmosphere would you find the air you breathe?

5. In which layer of Earth’s atmosphere does ozone form? Explain how it forms.

Class
































Name

Date


A Scientific Method e r u s C t a a I F n d I f e T W N A o t s p h E L t I e t C c c u a c r S F a t

NT E RIME N

P E X

S

D

R O E


s t s i n Y s d e e y R e t m r n i O h a r E t o e H o p p T y p p m y u x H s b e

Y

Class

E Y

S R I V O E E

R H































Name

Date


A Scientific Method 1.

Define the term scientific method .

2.

What is typically the first step in a scientific method? Give two examples.

3.

What is a hypothesis?

4.

Compare and contrast a hypothesis and a theory.

Class
































Name

Date


Laboratory Safety

Class


































Name

Date


Laboratory Safety 1. What should you do before entering the lab? List at least three things.

2. What should you do if a chemical comes in contact with your skin?

Class


































Name

Date

CHAPTER

1

Class

STUDY GUIDE

Introduction to Chemistry Introduction Section 1.1

A Story of Two Substances

In your textbook, read about the ozone layer. Use each of the terms below just once to complete the passage. atmosphere

oxygen gas

ozone

stratosphere

troposphere

ultraviolet radiation

ozone hole

































Name CHAPTER

Section 1.2

Date

1

Chemistry and Matter

In your textbook, read about chemistry and matter matter.. Define each term. 1. chemistry

2. matter

Class

STUDY GUIDE

































Name

Date

CHAPTER

Section 1.2

1

continued

Identify each branch of chemistry described. 21. The study of the matter and processes of living things

22. The study of carbon-containing chemicals

23. The study of the components and composition of substances

Class

STUDY GUIDE

































Name CHAPTER

Section 1.3

Date

1

Class

STUDY GUIDE

Scientific Methods

In your textbook, read about a systematic approach that scientists use. Use the words below to complete the concept map. Write your answers in the spaces below the concept map. conclusions

experiments

OBSERVATIONS Existing knowledge Qualitative data

hypothesis

scientific law

theory 4.

R Y

Hypothesis supported



































Name

Date

CHAPTER

Section 1.3

1

continued

Circle the letter of the choice that best completes the statement.

Class

STUDY GUIDE



































Name CHAPTER

Section 1.4

Date

1

Scientific Research

Class

STUDY GUIDE



































Name

CHAPTER

Date

1

CHAPTER ASSESSMENT

Introduction to Chemistry Introduction

Class



































Name CHAPTER

Date

1

Understanding Main Ideas (Part A)

Class

CHAPTER ASSESSMENT



































Name CHAPTER

Date

1

Understanding Main Ideas (Part B)

Class

CHAPTER ASSESSMENT









































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































Name

Date


States of Matter

Class


e t a t s s u o e s a G

. c n I , s e i n a p m o C l l i H w a r G c M e h T f o n o i s i v i d a , l l i H w a r G c

e t a t s d i l o S e t a

M / e o c n e l G © t h g i r y































Name

Date

Class

7


States of Matter

Use with Chapter 3, Section 3.1

1. Name the physical states in which almost all matter exists.

2. In which state(s) of matter are the molecules most compressed?

3. In which state(s) of matter do the molecules fill the entire volume of a container?

4. In which state(s) does matter take the shape of a container?

5. Compare the distance between the molecules of a gas in a very small container with the distance between the molecules of the same gas in a very large container. Explain your answer.

. c n I , s e i n a p m o C l l i H w a r G c M e h T f o n o i s i v i d a , l l i H w a r G c M / e o c n e l G © t h g i r y

6. What happens to the volume of a liquid when it is poured from a small container into a large container?

7. Suppose you fill a glass with ice cubes. When the ice cubes melt, is the glass still full? Explain your answer.

8. Suppose you fill a container with steam and then seal the container. When the steam in the container changes to liquid water at room temperature, will the container still be full? Explain your answer.































Name

Date


Conservation of Mass

Class

8 Use with Chapter 3, Sections 3.2
































Name

Date

Class

8


Conservation of Mass

Use with Chapter 3, Sections 3.2

1. What happens when mercury(II) oxide is heated?

2. What does the law of conservation of mass state?

3. Write the law of conservation of mass in mathematical terms.

4. Assume that the test tube shown in the transparency started out having 15.00 g of mercury(II) oxide. After heating the test tube, you find no mercury(II) oxide left and 1.11 g of oxygen gas. What mass of liquid mercury was produced by the chemical reaction? Show your work.


5. Assume that the test tube shown started out having 10.00 g of mercury(II) oxide. After heating the test tube briefly, you find 1.35 g mercury(II) oxide left and 8.00 g of liquid mercury. How much oxygen gas was produced by the chemical reaction? Show your work.

6. Suppose you heat some mercury(II) oxide in a test tube similar to the one shown. After the chemical reaction, you find 12.5 g of liquid mercury and 1.0 g of oxygen gas. There is no mercury(II) oxide left in the test tube. How much mercury(II) oxide did you start with? Show your work.































Name

Date

Class

9


Types of Matter


Matter

Can it be separated by physical means? yes

no

Mixtures

Pure substances

Is the composition uniform?

Can it be broken down by ordinary chemical means?

yes

Homogeneous mixtures lemonade, gasoline, steel

no

Heterogeneous mixtures dirt, blood, milk

yes

Compounds salt, baking soda, sugar

no

Elements oxygen, gold, iron


































Name

Date

Class

9


Types of Matter


1. Into what two broad classes can all matter be divided?

2. What is the difference between a mixture and a pure substance?

3. What is the difference between a compound and an element?

4. Can a compound be a heterogeneous mixture? Explain your answer by referring to the diagram.

given below. below. Circle the substances that are elements. 5. A list of compounds and elements is given . c n I , s e i n a p m o C l l i H w a r G c M

gold

aluminum

water

sugar

oxygen

platinum

salt

chlorine

brass

6. How can you tell the difference between a homogeneous mixture and a heterogeneous mixture?































Name

Date

Class

10 1 0


Mass Percentage and the Law of Definite Proportions


% 0 0 1 

e s o r c u S f o n ) o s i t s i a s o m p y b m ( o C

n % o 0 b r 2 . a 2 C 4

n % e 0 g 3 y . x 1 O 5

t d n n u e o m p e l m e o f c o f s o s s a s m a m 

) % ( t n e m e l
































Name

Date

Class

10 1 0


Mass Percentage and the Law of Definite Proportions


Your analysis shows 1. Suppose you analyze the composition of an unnamed compound. Your that the compound is 51.30% oxygen, 42.20% carbon, and 6.50% hydrogen by mass. What can you conclude about the compound?

2. What is the mass percentage of carbon in 5.000 g of sucrose? 50.00 g of sucrose? 500.0 g of sucrose? Explain.

3. How many grams of oxygen are in 50.00 g of sucrose? Show your work.

4. How many grams of carbon are in 100.0 g of sucrose? Show your work.


5. How many grams of hydrogen are in 6.0 g of sucrose? Show your work.































Name

Date

Class

2

MATH SKILLS TRANSPARENCY MASTER

Visualizing the Conservation of Mass


, n e g 2 o H r d y H

+

s

t , c e d u i x d o o r r d y P h H O K m u i s s a t o P
































Name

Date

Class

2

MATH MA TH SKILLS TRANSP TRANSPARENCY ARENCY WORKSHEET W ORKSHEET

Visualizing the Conservation of Mass


1. How many potassium atoms are in the reactants of the chemical reaction shown? How

many are in the products? 2. How many oxygen atoms are in the reactants of the chemical reaction shown? How many

are in the products? 3. How many hydrogen atoms are in the reactants of the chemical reaction shown? How

many are in the products? 4. Assume that the chemical reaction shown started out having a total of 15 g of potassium and water. How much potassium hydroxide and hydrogen gas will be produced by the chemical reaction? Show your work.

5. Assume that the chemical reaction shown started out having 6 atoms of potassium and 6 molecules of water. How many molecules of potassium hydroxide will be produced by the chemical reaction? How many hydrogen atoms will result? . c n I , s e i n a p m o C l l i H w a r G c M

6. Assume that you are working with a chemical reaction that decomposes water into hydrogen and oxygen. You begin with 36 grams of water and end with 32 grams of oxygen. If all of the water decomposes, how many grams of hydrogen gas will result?

































Name

Date

Class

3

MATH SKILLS TRANSPARENCY MASTER

Finding Percent by Mass

% 2 . 2 4

n o b r a c

% 0 5 . 6

n e g o r d y h


% 0 3 . 1 5







% 0 0 1

% 0 0 1

% 0 0 1







n e g y x o % 2 . 2 4

% 0 5 . 6































Name

Date

Class

3

MATH MA TH SKILLS TRANSP TRANSPARENCY ARENCY WORKSHEET W ORKSHEET

Finding Percent by Mass


1. What percentage of the 20.0 g sample does sugar (sucrose) represent? 2. What is the percent by mass of oxygen in sugar? Of carbon? Of hydrogen?

3. How many grams of oxygen are in 100 g of sucrose?

4. How many grams of carbon are in 30.0 g of sucrose? Show your work.

sodium, 1.51 g of hydrogen, 18.02 g of 5. A sample of baking soda contains 34.48 g of sodium, carbon, and 72.00 g of oxygen.































Name

Date

CHAPTER

3

Class

STUDY GUIDE

Matter—Properties and Changes Matter—Properties Section 3.1

Properties of Matter

In your textbook, read about physical properties and chemical properties of matter. matter. Use each of the terms below just once to complete the passage. chemical

mass

physical

density

properties

substance

Matter is anything with (1) (2)

and volume. A

is a form of matter with a uniform and unchanging composition.

Substances have specific, unchanging (3)

that can be observed.

Substances have both physical and chemical properties. (4) properties can be observed without changing a substance’s chemical composition. Color, hardness, and (5)

are examples. Other properties cannot be































Name

Date

CHAPTER

Section 3.1

3

continued

In your textbook, read about states of matter matter.. Label each drawing with one of these words: solid , liquid , gas. 18.

19.

Class

STUDY GUIDE































Name

Date

CHAPTER

Section 3.2

3

Class

STUDY GUIDE

Changes in Matter

In your textbook, read about physical change and chemical change. What kinds of changes do these words indicate? Write each word under the correct heading. Use each word only once. boil

crumple

crush

explode

burn

ferment

freeze

grind

condense

melt

oxidize

rot

corrode

rust

tarnish

vaporize

Physical Change

Chemical Change

1.

9.

2.

10.

3.

11.

4.

12.

5.

13.

































Name CHAPTER

Section 3.3

Date

3

Class

STUDY GUIDE

Mixtures of Matter

In your textbook, read about pure substances and mixtures. Use the words below to complete the concept map. heterogeneous

salt–water mixture

sand–water mixture

mixtures

solutions

water

matter

































Name

Date

3

CHAPTER

Section 3.4

Class

STUDY GUIDE

Elements and Compounds

In your textbook, read about elements and compounds. Circle the letter of the choice that best completes the statement or answers the question.

substances by physical or chemical 1. A substance that cannot be separated into simpler substances means is a(n) a. compound.

b. mixture.

c. element.

d. period.

2. A chemical combination combination of two or more different different elements is a(n) a. solution.

b. compound.

c. element.

d. period.

































Name

Date

CHAPTER

Section 3.4

3

Class

STUDY GUIDE

continued

18. Sucrose is 51.50% oxygen. How many grams of oxygen are in 20.0 g of sucrose? Show your work.

19. A 2-g sample of sucrose is 6.50% hydrogen. What is the mass percentage percentage of hydrogen in 300 g of sucrose? Explain your reasoning.

































Name

Date

CHAPTER

3

Class

CHAPTER ASSESSMENT

Matter—Properties and Changes Matter—Properties Reviewing Vocabulary Match the definition in Column A with the term in Column B. Column A

homogeneo geneous us mixture 1. A homo 2. States that mass is neither created nor destroyed in a chemical reaction

Column B a. law of multiple proportions b. percent by mass

































Name CHAPTER

Date

3

Class

CHAPTER ASSESSMENT

Understanding Main Ideas (Part A) Identify each property as either physical or chemical . Tell whether each physical property is extensive or intensive. 1. color 2. tendency to rust 3. boiling point 4. density



































Name CHAPTER

Date

3

Understanding Main Ideas (Part B)

Class

CHAPTER ASSESSMENT



































Name CHAPTER

Date

3

Thinking Critically

Class

CHAPTER ASSESSMENT



































Name CHAPTER

Date

3

Applying Scientific Methods

Class

CHAPTER ASSESSMENT



































Name CHAPTER

Date

3

Applying Scientific Methods,

Class

CHAPTER ASSESSMENT continued

5. Calculate the mass percentage of A in each of the chemist’s samples. samples. Show your calculations.



































Name

Date

CHAPTER 3

Assessment

Student Recording Sheet

Standardized Test Practice Multiple Choice

Class









































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































TEACHER GUIDE AND ANSWERS

14. a. 12.56 km

6. b

b. 1.001

7. i

c. 100.0

8. g

d. 23.34 15. a. 13 b. 12.738 c. 12.7835 d. 12.78346 16. a. 121

9. c 10. a 11. second 12. meter 13. kilogram 14. liter 15. Density

b. 120.8

16. Significant figures

c. 120.75

Understanding Main Ideas (Part A)

d. 120.7524 17. a. 115.6 kg b. 4.25 cm c. 2

m3

d. 1.90 m/s

1. one is estimated and three are known

derived ed unit unit of volu volume me 2. deriv 3. true 4. 1.234  106 5. Answ Answers ers may vary: 6 km km (1  103 m/1 km) =

6  103 m or 6 km  1000 m/1 km = 6000 m

Section 2.4 Representing Data

6. 1 s ÷ (1  103 ms/s) = 1  103 s

1. circle graph

7. 34 g  109ng/g = 3.4  1010ng

2. bar graph

8. 1  1015 or 1,000,000,000,000,000

3. 60%

9. 2  104 or 20,000

4. Au August; gust; No Novemb vember er 5. 7 6. 3 7. 1 8. 5 9. 2 10. 6 11. 4

10. (100 km/h)  (1000 m/1 km)  (1 h /60 min) 

(1 min/60 s) = 27.8 m/s = 30 m/s 11. 0.3  1010 + 5  109 = 5.3  1010 = 5  1010 12. 5.01  10-7 –30  10-9 = 5.01  10-7 –0.3 10-7

= 4.  10-7 = 4.7  10-7 Understanding Main Ideas (Part B) 1. d 2. c 3. b

Chapter Assessment – Chapter 2 — Analyzing Data Reviewing Vo Vocabulary cabulary 1. d

4. d 5. a 6. a

































bar graph, graph, in which which alum aluminum inum,, steel steel,, and wood wood havee bars hav bars of lengt length h 1, nyl nylon on has has a bar bar of leng length th 2, and carbon-fiber-reinforc carbon-fiber-reinforced ed plastic has a bar of len length gth 3. 4. No; alth although ough steel is stron strong, g, stiff stiff,, and

inexpensive, it is also also very dense. 5. Answers will vary. vary. Students may say say that they

would prefer a racket with a frame made of carbon-fiber-reinforced carbon-fiber-r einforced plastic because it is strong, stron g, stiff, and not not very very dense. dense. Applying Scientific Methods

percent error can be misleading. misleading. Conclusions drawn from the data on Samples A and B could lead to misidenti misidentifica fication tion of the metals. metals. Only the the data for Sample C is reliable. 8. Accep Acceptt all reasonable answers. answers. Students may

suggest that she she note the the appearance of her samples next time, that she measure measure only the sample and not the container container it is in, that she use proper rounding conventions conventions when recording data, or that she ensure ensure that her equipment is calibrated so that her measurements will be more accurate.

Samplee A: 8.060 g/mL g/mL 1. Sampl Samplee B: 8.836 g/mL Sampl g/mL Samplee C: 7.24 g/mL Sampl g/mL measurements for Samples A and 2. The student’s measurements C are very precise. precise. The data for these these two samples is consistent. 3. Accep Acceptt all supported answers. answers. Students may

suggest that Sample A could be iron, iron, Sample B could be either copper or nickel, nickel, and Sample C could be tin. tin. Students should suggest that additional information is needed and perhaps further tests need to be made before the samples can be identified accurately. . c n I , s e i n a p m o C l l i H w a r G c M e h T f o n o i s i v i d a , l l i H w a r G c M / e o c n e l G © t h g i r y

4. Students may suggest noting the color of each

metal. Color is probably probably the most practical practical and distinguishing feature of the metals. 5. percent error = error/accepted value  100%

percent error of sample A = 8.92 g/mL g/mL 8.060 g/mL g/m L ÷ 8.9 8.92 2 g/mL g/mL  100% = 9.64% percent error of sample B = 8.90 g/mL – 8.836 g/mL ÷ 8.90 g/mL  100% = 0.719 % percent error of sample C = 7.28 g/mL – 7.24 g/mL ÷ 7.28 g/mL  100% = 0.549% 6. A bar graph would best compare the densities

of each sample sample because the relative heights of the bars would would compare compare the density density of each sample. A pie chart would would not make sense sense in this case because there are no parts or whole. Students may also make a case for line graphs; however the curves will be difficult to compare

CHAPTER 3 MiniLab 3 – Observe Dye Separation Analysis 1. Drawings should show the filter paper with the

ink spot in the center and different dyes spreading out from the center. 2. Different components components of the ink have varying varying

attraction for the the filter filter paper. paper. Therefore, the colors that comprise the ink will be deposited at different distances distances from the center of the paper. paper. 3. Answers will vary. vary. Different makes makes and types of

black ink have different dyes in them. Expected Results: As the water spreads out on

the paper, paper, different dyes in the the ink will spread out from the center and be deposited on the filter paper at different distances from the center.

ChemLab 3 – Identify the Products of a Chemical Reaction Pre-Lab 3. A physical property is a characteristic that can

be observed or measured without changing the substance’ss composition—for example, color substance’ color,, shape, shap e, or mass. mass. A chemical chemical property property is the the ability of a substance substance to combine combine with or change into one or more other substances—for example, reactivity with water. water.
































b. You might observe a change in shape or in

physical state, physical state, such as boiling, cond condensin ensing, g, freezi fre ezing, ng, mel meltin ting, g, eva evapor porati ating, ng, dis dissol solvin ving, g, or crystallizing. 5. A homogeneous mixture is one in which one or

more substances are evenly distributed throughout another another substance. A heterogeneous mixture is one in which there is an observable separation of component substances. Reaction Observations Time

Observations

(min) 5

Students should observe gradual formation of gray solid on the copper

10

wire. The solution will turn blue-green.

15

6. The liquid’s volume remains the same,

regardles rega rdlesss of the size size of the contain container er.. the ice cubes melt, the resulting liquid liquid 7. When the water will not fill the glass because there were air spaces within the ice cubes. The liquid will conform to the shape of the container container and fill it only partially. 8. The liquid water will not fill the container

because the molecules of the liquid will be much closer together than the molecules of the steam were.

Teaching Transparency 8 – Conservation of Mass 1. A chemical reaction occurs in which

mercury(II) oxide becomes liquid mercury and oxygen gas. 2. Mass is neither created nor destroyed in any

20

Flame test: blue-green color

process.

Analyze and Conclude

3. Massreactants = Massproducts

1. A grayish solid formed on the wire. The


solution turned turned blue-green. Yes, a solid formed and a color change change occurred. The products are silver and copper nitrate. 2. Silver metal is white white to gray. gray. Copper nitrate is

blue-green. 3. Experimental results should agree with blue-

green light. 4. homogeneous; heterogeneous and

homogeneous Inquiry Extension

The copper wire might not have been clean. The better observations will be more detailed.

Teaching Transparency 7 – States of Matter solid, id, liq liquid uid,, gas 1. sol

Massmercury(II) oxide = Massmercury + Massoxygen 15.00 g = Massmercury + 1.11 g Massmercury = 13.89 g 5. Massreactants = Massproducts

Massmercury(II mercury(II)) oxide used in the reaction reaction = Massmercury + Massoxygen 10.00 g – 1.35 g = 8.00 g + Mass oxygen Massoxygen = 0.65 g 6. Massreactants = Massproducts

Massmercury(II) oxide = Massmercury + Massoxygen Massmercury(II) oxide = 12.5 g + 1.0 g Massmercury(II) oxide = 13.5 g

Teaching Transparency 9 – Types of Matter

2. solid

1. mixtures and pure substances

3. gas

2. A mixture can be separated into its component

































accordi ording ng to the diagram, a heterogeneo heterogeneous us 4. No; acc mixture can be separated into its components by physical physical means. A compound cannot cannot be separated into its components by physical means. 5. gold, alum aluminum inum,, oxy oxygen, gen, chl chlorine, orine, plati platinum num 6. A homogeneous mixture has a uniform

composition, whereas a heterogeneous heterogeneous mixture mixture does not. Thu Thus, s, if you can see the the differ different ent components in a mixture, then it is a heterogeneous mixture. 7. a. homogeneous b. heterogeneous c. heterogeneous

percentage of an element (%) = mass of 6. mass percentage element/ma eleme nt/mass ss of comp compound ound  100% mass percentage percentage of chlorine = 12.13 12.13 g/20.00 g  100% = 60.65% mass percentage percentage of sodium = 7.87 g/20.00 g  100% = 39.35% 7. Students should show a circle graph divided

into two two wedges: one representing representing approximately approxim ately 60% of the circle and and one representing approximately approximately 40% of the circle.

Math Skills Transparency 2 – Visualizing the Conservation of Mass

d. heterogeneous

1. 2; 2

e. homogeneous

2. 2; 2

f. homogeneous

3. 4; 4

g. heterogeneous 8. Separation methods include filtration,

distillation, distillat ion, crysta crystalliz llization ation,, and chromatography.


mass of hy hydrog drogen en = 6.50%  6.0 g/100% = 0.39 g

Teaching Transparency 10 – Mass Percentage and the Law of Definite Proportions 1. It is sucrose.

42.20%; %; the mass mass percent percentage age of carbo carbon n is 2. 42.20 consistent consiste nt regardles regardlesss of the amount amount of sucr sucrose; ose; this is the the law of definite proportions. proportions. percentage of oxygen = mass of 3. mass percentage


If the reactant reactantss total 15 15 g, then the the products products will total 15g. 5. Massreactants = Massproducts

There will be 6 molecules molecules of potassium hydroxide hydr oxide and 12 atoms of hydr hydrogen. ogen. 6. Massreactants =Massproducts

Masswater = Masshydrogen + Massoxygen Masshydrogen = Masswater – Massoxygen Masshydrogen = 36 g – 32 g = 4 g 7. Massreactants = Massproducts

oxygen/m oxy gen/mass ass of sucr sucrose ose  100%

Masssodium + Masschloride = Masssodium chloride

51.30% 51.30 % = mass of oxy oxygen/5 gen/50.00 0.00 g  100%

Masssodium = Masssodium chloride – Masschloride

mass of of oxy oxygen gen = 51.30% 51.30%  50.00 g/100% = 25.65 g

Masssodium = 116.90 g – 70.9 g = 46.0 g

percentage age of carbon = mass of 4. mass percent carbon/mas carbo n/masss of sucr sucrose ose  100% 42.20% 42.20 % = mass of carbon carbon/100. /100.0 0 g  100% of carbo carbon n = 42.20% 42.20%

100.0 g/100% =

Math Skills Transparency 3 – Finding Percent by Mass 1. 100% 2. 51.30 51.30% % oxygen; oxygen; 42.2% carbon; carbon; 6.50% hydrog hydrogen en
































Masss percentage percentage of carbo carbon n = mass of 4. Mas

17. physical

carbon/mas carbo n/masss of sucr sucrose ose  100

18. gas

42.2% = mass mass of carbon carbon/30.0 /30.0  100

19. solid

mass of oxy oxygen gen = 42.2/30.0 42.2/30.0  100 = 140.7 g = 141 g

20. liquid

5. a. 34.48 g + 1.51 g + 18.02 g + 72.00 g =

126.01 g b. Mass percentage percentage of element = mass mass of

element/ma eleme nt/mass ss of baki baking ng soda  100 Mass percentage Mass percentage of sodi sodium um = (34.48/126.01)  100 = 27.36% Mass percentage of hydr hydrogen ogen = (1.51/126.01)  100 = 1.20% Mass percentage of carbon = (18.02/126.01)  100 = 14.30% Mass percentage percentage of oxygen = (72.00/126.01)  100 = 57.14% 6. Students should show a circle graph divided

into four wedge wedges: s: sodiu sodium, m, 27.36 27.36%; %; hy hydroge drogen, n, 1.20%; 1.2 0%; car carbon bon,, 14. 14.30% 30%;; and oxygen oxygen,, 57. 57.14% 14%.. part, the whole whole 7. a part,

Study Guide – Chapter 3 – Matter— Properties and Changes Section 3.1 Properties of Matter Matter 1. mass 2. substance 3. properties 4. Physical 5. density 6. chemical 7. physical 8. chemical 9. chemical 10. physical 11. physical

21. true 22. false 23. true 24. false 25. false 26. false 27. false 28. false Section 3.2 Changes in Matter 1. boil 2. freeze 3. condense 4. vaporize 5. melt 6. grind 7. crumple 8. crush 9. explode 10. rust 11. oxidize 12. corrode 13. tarnish 14. ferment 15. burn 16. rot 17. c 18. a 19. d 20. e 21. b



































Section 3.3 Mixtures of Matter Matter 1. mixtures 2. water 3. heterogeneous 4. sand-water mixture 5. solutions 6. salt-water mixture 7. b

is two times the mass ratio ratio of oxygen to to hydrogen in H2O. This follows follows the law of multiple proportions.

25. No; they have have different different proportions proportions of hy hydrog drogen en

and oxygen.

Chapter Assessment - Chapter 3 — Matter––Properties and Changes Reviewing Voc Vocabulary abulary

8. c

1. f

9. d

2. d

10. a

3. e

Sectio Sec tion n 3.4 Ele Elemen ments ts and Com Compo pound unds s

4. a

1. c

5. c

2. b

6. b

3. d

7. i

4. c

8. g

5. d

9. h

6. b

10. k

7. element

11. j

8. compound

12. Both are are characteris characteristics tics of subst substanc ances. es. A

9. element . c n I , s e i n a p m o C l l i H w a r G c M

hydrogen ogen in H2O2 24. The mass ratio of oxygen to hydr

10. element 11. compound 12. Ne 13. Ca 14. Fe

physical property property can be observed without changing chan ging the composit composition ion of the substanc substance. e. A chemical property property is the ability or tendency of a substance to change into another substance. are kinds of matte matterr. A substance substance cannot cannot be 13. Both are separated into other substances by physica physicall means. A mixture can be separated into two or more substances.
































12. c 13. salt 14. air 15. aluminum Understanding Main Ideas (Part B) 1. physical 2. chemical 3. chemical 4. physical 5. chemical 6. physical 7. chemical 8. homogeneous 9. heterogeneous 10. homogeneous 11. heterogeneous

Usingg the mass percentage percentage equation: (2.02 g c. Usin hydrogen)58.33 g milk of magnesia  100% hydrogen)58.33 = 3.46% hydrogen d. law of defin definite ite proportion proportionss Applying Scientific Methods

Sample le 1: 2.00 g A/1.00 A/1.00 g B 1. Samp Sample Samp le 2: 2.000 g A/1.000 A/1.000 g B Sample Samp le 3: 4 g A/1 g B Sample Samp le 4: 2.0 g A/1.0 A/1.0 g B Samples les 1, 2, and 4 hav havee the same same ratio. ratio. Sampl Samplee 2. Samp 3 has a different ratio. Samples les 1, 2, and 4 are are the same same compound, compound, 3. Samp according to the law according law of definite proportions. proportions. Sample 3 is a different compound because its ratio of mass A to mass B differs from from the ratios in samp samples les 1, 1, 2, and 4. 4. The chemist could calculate the mass

13. heterogeneous

percentage of A or B in each each sample and compare the percentages with the percentages of the desired desired compoun compound. d.

14. heterogeneous

5. a. (6.42 g A)9.63 g sample  100% = 66.67% A

12. homogeneous

15. heterogeneous 16. heterogeneous

b. (63.75 g A)95.62 g sample  100%

= 66.67% A

17. homogeneous

c. (32 g A)40 g sample  100% = 80% A

18. homogeneous

d. (17.0 g A)25.5 g sample  100% = 66.67% A

19. dis distil tilla latio tion n 20. filtration Thinking Critically

chemist was looking for 6. Yes; the compound the chemist is in sampl samples es 1, 2, and 4. In all all three three samples, samples, the mass percent percentage age of A is 66.67%. Ac Accor cording ding to the law law of defin definite ite proporti proportions, ons, a compound compound

































CHAPTER 4 MiniLab 4 – Model Isotopes Analysis

relative number of pre- and post-1982 1. The relative pennies in the bag determines the percentage abundanc abun dancee of each group. group. mass of a penny depends upon the 2. The atomic mass mixture of pennies each each student receives. Sample data is shown here. mass contribution (pre-1982) = (55.0%)(3.11 g) = 1.71 g mass contribution (post-1982) = (45.0%)(2.55 g) = 1.15 g atomic mass = (1.71 g + 1.15 g) = 2.86 g 3. A different mixture would have a different

relative abundance abundance and a different atomic mass. pennies will vary vary due to 4. Masses of individual pennies wear. Expected Results:


Pre-1982 pennies have a greater mass than post1982 pennies. Mass of ten pre-1982 pennies = 31.10 31.10 g Average mass of a pre-1982 penny penny = 3.11g Mass of ten post-1982 pennies = 25.48 25.48 g Average mass of a post-1982 penny penny = 2.55 g The atomic mass depends on the mixture analyzed.

ChemLab 4 – Calculate the Atomic Mass of the Element “Snackium” Pre-Lab

Answers ers will vary. vary. The students students should should find 3. Answ that the atomic mass is closest to the most abundant abun dant piec piece. e. In the the sample sample data, data, the atomi atomicc mass is closer to the chex pieces than the pretzels or bagel chips due to their high percent 4. Answers will vary. vary. Students should realize realize that

the small sample size and difference in samples will lead to differences. 5. The atomic mass is different from the mass

number because it is an average and therefore will not be a whole number. 6. Answers will vary depending on the reference

sources used. sources used. They should should find find most elements elements have numerous natural isotopes. 7. The error in the lab is due to small sample size.

The experiment could be modified by starting with a much larger sample size. Inquiry Extension

Answers will vary. vary. The students should be able to predict the most abundant element based on the atomic mass listed on the periodic table.

Teaching Transparency 11 – Cathode Ray Experiments 1. A cathode ray is a beam of negatively charged

particles or electrons. vary. All three experiments have a 2. Answers may vary. voltage source, voltage source, a cathode, cathode, an anode, anode, gas at low pressure, and a phosphor phosphor that allows allows the position of the cathode ray ray to be determined. 3. The cathode ray travels from the cathode
































Teaching Transparency 12 – Understanding Rutherford’s Gold Foil Experiment alpha particles, which 1. The arrows represent alpha have a positive (2+) charge. 2. diagram A 3. diagra diagram m B; some of the alpha alpha particl particles es were were

deflected at large angles. 4. Rutherfor Rutherford d concluded that the plum pudding

model of of the atom atom was incorr incorrect. ect. He also also concluded that an atom is made mostly of empty space with a tiny tiny,, dense, centrally located nucleus that is positively charged and contains almost all of the atom’s atom’s mass. 5. The massive alpha particles were expected to be

largely unaffected by the much less massive electrons. electr ons. The weak, diffu diffusely sely distributed distributed positive charge inside the atom was also not expected to affect the positively charged alpha particles.

Teaching Transparency 13 – Isotopes 1. a. electron b. neutron c. proton 2. Protons and neutrons are in the nucleus.

identify the 3. The number of protons in an atom identify atom as a particular element. 4. The protons and electrons in an atom have

opposite charges and are equal in number.

draw two atomic nuclei, nuclei, each 8. Students should draw surrounded by an electron cloud. cloud. Both atoms should have three protons in the nucleus and threee electrons thre electrons in the electro electron n cloud. cloud. One of the atoms should have three neutrons in the nucleus; the other should have have four neutrons in the nucleus.

Teaching Transparency 14 – Radioactive Particles 1. Alpha particles have have the greatest greatest mass. Gamma

rays have no mass. 2. Answers may vary. vary. Answers should include include the

fact that gamma rays have no mass and are often characterized as light (waves). 3. Because they have have opposite charges, charges, the

positively charged alpha particles are attracted to the negatively charged plate. 4. The beta particles are attracted to the positively

charged plate. Their curvature is greater greater because they have a much smaller mass than alpha particles do and are therefore more greatly affected by the electric field. 5. Gamma rays have no charge; charge; therefore, they are are

not attracted to either charged plate.

Math Skills Transparency 4 – Calculating Atomic Mass numbers are the mass number of each 1. The numbers isotope. The mass numbers numbers refer to the the sum of each isotope’s isotope’s protons and neutrons, which makee up most of the mass mak mass of an atom. atom.

































5. The discovery of 8Li will have a very small effect

on lithium’s atomic mass because the percent abundance of 8Li is so small. 6. Mass contribution = (mass)(percent

The pit should be labeled nucleus and should include labeled protons protons and neutrons. neutrons. The outer circle of the peach should be labeled labeled electrons.

abundance) 185X :

(184.953 amu)(0.3740) amu)(0.3740) = 69.17 69.17 amu

187X :

(186.956 amu)(0.6260) amu)(0.6260) = 117.0 117.0 amu

Atomic mass of X of X = = 69.17 amu 1 117.0 amu = 186.2 amu 7. Mass contribution = (mass)(percent

Particle

Symbol

Location

Relative Charge

Relative Mass

6. Proton

p

In the nucleus

1

1

7. Neutron

n0

In the nucleus

0

1

8. Electron

e

In the space surrounding

1

1/1840

the nucleus

abundance) 113X :

(112.904 (112. 904 amu)(0.0430 amu)(0.0430)) = 4.86 amu

115X :

(114.904 amu)(0.9570) amu)(0.9570) = 110.0 110.0 amu

Atomic mass of X of X = = 4.86 amu + 110.0 amu = 114.9 amu The element is indium.

Section 4.3 How Atoms Atoms Differ Differ 1. false 2. true 3. true 4. true

Study Guide – Chapter 4 – The Structure of the Atom Section 4.1 Early Ideas About Matter Matter 1. false 2. true 3. true . c n I , s e i n a p m o C l l i H w a r G c M

4. true 5. false 6. false 7. true 8. true 9. false

5. false

protons; 82 electrons electrons 6. 82 protons; 7. 8 protons 8. 30 9. 85

protons; 104 electrons electrons 10. 104 protons; 11. 84 protons; protons; 84 electrons electrons 12. 102 protons; protons; 102 electrons electrons

protons, 19 electrons, electrons, 20neu 20neutron tronss 13. 19 protons, protons, 14 electrons, electrons, 14 neutrons neutrons 14. 14 protons, 15. 19 protons, protons, 19 electrons, electrons, 21 neutrons neutrons


































Chapter Assessment - Chapter 4 — The Structure of the Atom

26. d 27. 76 28. Nb

Reviewing Vo Vocabulary cabulary

29. 190.2

1. g

30. atomic mass units

2. d

osmium ium:: 76 proton protons, s, 76 electro electrons; ns; nio niobiu bium: m: 41 31. osm

3. e

protons, prot ons, 41 electr electrons. ons. 32. Mass contribution = (mass)(percent

abundance)

4. a 5. c 6. b

63X :

(62.930 amu)(69.17%) amu)(69.17%) = 43.53 amu

7. f

65X :

(64.928 amu)(30.83%) amu)(30.83%) = 20.02 amu

8. i

Atomic mass of X of X = = 43.53 amu + 20.02 amu = 63.55 amu

9. h

The element is copper. 33. Mass contribution = (mass)(percent

abundance)

10. k 11. m 12. j

35X :

(34.969 amu)(75.77%) amu)(75.77%) = 26.50 amu

13. l

37X :

(36.966 amu)(24.23%) amu)(24.23%) = 8.957 amu

atoms. The mass number number is the 14. Both pertain to atoms.

Atomic mass of X of X = = 26.50 amu + 8.957 amu = 35.46 amu

sum of the protons and neutrons in the nucleus nucleus of a given given atom. atom. The atomic atomic number number is the the number numb er of prot protons ons in an atom
































14.

65Cu, 29

29,, 29 29

15. Uran ranium ium-23 -235, 5, 92, 92, 143 Understanding Main Ideas (Part B) 1. h 2. b 3. f 4. a 5. c 6. e 7. d 8. g 9. Mass contribution = (mass)(percent

abundance) 69Ga: (68.9257 amu)(60.12%) amu)(60.12%) = 41.44 41.44 amu 71Ga: (70.9249 amu)(39.88%) amu)(39.88%) = 28.28 28.28 amu Atomic mass mass of Ga = 41.44 amu + 28.28 amu = 69.72 amu 10. Mass contribution = (mass)(percent

abundance)

1.140 amu = 2x 2x amu amu x = x = 0.570 Percent abundance of 121Sb = 57.0% Percent abundance of 123Sb = 1 – x x = = 1 0.570 = 43.0% Applying Scientific Methods 1. Isot Isotopes opes 1, 1, 2, 4, and 5 are the same same element; element;

they all have have 24 protons. Isotopes 3 and 6 are another element; they both have have 26 protons. protons. 2. Answers may vary. vary. Although the masses of

protons and neutrons, neutrons, which make up most of the mass mass of an atom, atom, are very very close to to 1 amu, they are are not exactly exactly 1 amu. Thus Thus,, the mass of each isotope is very close to a whole number, but is not exactly a whole number. 3. Mass contribution = (mass)(percent

abundance) Isotope 1: (49.946 amu)(4.35%) = 2.17 amu Isotope 2: (51.941 amu)(83.80%) = 43.53 amu Isotope 4: (52.941 amu)(9.50%) = 5.03 amu Isotope 5: (53.939 amu) (2.35%) (2.35%) = 1.27 amu

Chemistry Matter of Change

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