Focus on California 8th Grade Physical Science Textbook Chapter 1 Introduction to Physical Science

Chapter Introduction to Physical Science Standards Preview All objects experience a buoyant force when immersed in a . As a basis for ing this concept Students know density is mass per unit volume . Students know how to calm late the density of substances ( regular and irregular solids and liquids ) from ments of mass and volume . progress is made by asking meaningful questions and conducting careful tions . As a basis for understanding this concept and addressing the content in the other three strands . students should develop their own questions and perform . Students will a . Plan and conduct a scientific investigation to test a hypothesis . Evaluate the accuracy and reproducibility ol data . Distinguish between variable and controlled parameters in a ( EST . Recognize the slope of the ear graph as the constant in the and apply this principle In inter graphs constructed from data . between linear and nonlinear relationships on a graph of data , is busy at work In a laboratory

. IRWIN The Work of Scientist VI , BIG Idea How do scientists investigate the natural world ?

Check What You Know Suppose you want to test whether sugar dissolves more quickly in cold water or hot water . How would you find out ?

How would you know if your answer is reliable ?

Vocabulary The images shown here represent some of the Key Terms in this chapter . You can use this vocabulary skill to help you understand the meaning of some Key Terms in this chapter . Academic Words words are terms that are frequently used in reading , writing , and diS ( These words are Key Terms they appear In many chapters at well as in other areas . Look for these words In context as you read this chapter . Definition Sentence constant Staying same temperature was kept lull stunt ) constant at the men ! 12 procedure The method of doing Follow the procedure explained ( some ' in the 44 the steps In TO . Du ( significant ad ) Having people ( Ill ) or voted aga bill ?

Apply It ! From the table above , choose the word that best completes each sentence . The amount of energy needed to move a piano IS . Be sure to follow the correct , during a fire drill . The driver maintained a speed .

Chapter Vocabulary Section ! em observing chemistry Section way I ?

scientific inquiry experiment hypothesis data communicating manipulated model Mme scientific theory responding name scientific law in Shadow Height i ' SI density weight Celsius Stale mass Kelvin sale 32 volume absolute zero A 30 i . Section 301 , 26 estimate significant ' at reproducibility 22 I . 20 Section I , graph line best fit 10 20 go 50 horizontal axis linear , axis slope and Light ( origin nonlinear ( data point Build Science Vocabulary Visit Web ( ode iii ( hunter

, to , Read ending . A . Preview Text Structure The information in this textbook is organized with red headings and blue Before you read , preview eath heading and ask a question to guide you as you read the topic . After you read , take notes to answer your questions . A graphic organizer like the one below can help you take notes I Write the heading in Write a question in column , Look for words in the head ing to guide you in asking a ( Answer your question in column . What Is Physical Science ?

Question Scientists What skills do li use skills Use scientists use to of observing , inferring . learn about the and predicting . natural world ?

The Study of Matter and Energy Apply It ! In your notebook , a graphic organizer for each in this chapter , Write a question for each heading . Alter you read . record answers In column .

Standards Investigation Design and Build a System How do you lind the density of something it you do have a balance to measure its mass ?

Suppose you ca use a graduated cylinder to measure the volume of such items as honey or table sugar . Can you build your own balance and devise a way to find the volume of items that are not easily measured with a ruler Your Goal To design and build a for data that ( an be used to the density of powdered solids and liquids To complete the investigation , you must I build a device to measure the masses of powdered solids and liquids develop a method to measure volume without using standard laboratory equipment obtain data you can use to the density of items follow the safety guidelines in Appendix A Plan It ! Preview the to lind out how mass , volume , and density are related . Research how are and how they work . Build a balance out of the materials supplied by your teacher Then devise a container with a known volume that you can use to find the volumes of your test materials . When your teacher approves your plan , test your system . Redesign and retest your system to improve its and reliability .

88 progress is made by ( questions and careful investigations . What skills do use to learn about the world ?

What do physical scientists study ?

Key ' SCIENCE observing inferring I I 60 An park is I great place to observe physical in action . What Is Physical Science ?

How Does a Ball Bounce ?

Your teacher will give you three balls and a meter stick . Hold the meter stick with the zero end tou ( hing the floor . Hold one ball beside the top of the meter stick so it touch . Drop the hall Have a partner the height of the first bounce . Repeat Step twice using the same ball . Repeat Step and for Eath oi the other balls . it Over Predicting Can you use your data to predict how ball will bounce in the future ?

Explain . As you walk around an park . you may wonder how lhe rides work , How does at ferris wheel spin ?

How do the bumper can work ?

makes the neon lights so colorful ?

Why do people out of the roller master as it completes ?

are all questions that ( cam help to answer . The designers of amusement parks must know great deal physical science In make sure that ence fun and thrills while staying safe .

Skills Scientists Use Science is the study of the natural world . Science includes all of the knowledge gained by exploring nature , To think and work like a scientist , you need to use the Santa skills that they do . use the skills of observing . inferring , and predicting to learn more about the natural world . For . More on thinking tom Web Code ( Observing Scientists observe things . Observing means using one or more to gather information . Your sexism include tight . hearing , touch . taste . and smell . Each day of your life . you observe things that help you decide what to eat . what to wear . and whether to stay inside or go out . Scientists usually make observations in a careful . orderly way . They make both qualitative and quantitative observations . Qualitative are descriptions that don ! involve hers or measurements . Noticing that a hall is round . that mill smells sour . or that a car is moving is at qualitative . Quantitative are . You make a observation when you measure your height or weight . science . observations may also be called Vid . or data . Inferring When you explain your . you are inferring . or an inference . inferences are based on reasoning from what you already know . You make inter all the time without thinking about it . For example . your gives lots of surprise quizzes . So if your teacher walks into the room carrying a stack of paper . you may infer that the pages contain a quiz . But inferences are not always correct , The papers could be to be taken home . Predicting Every day . people make statement about the future . Predicting means making a forecast of what will happen in the future based on past experience or evidence . For example . come scientists predict the weather based on past experience and current mation . Because a weather forecast is based on data . it is a prediction rather than a guess . What are band on ?

Flour Inferring when you explain or interpret your observations , you are making an inference . Inferring How do you think these young women obtained the stuffed bear ?

Explain your reasoning .

A A chemist is removing a liquid from a flask . FIGURE Careers in Physical Science People who work in physical study changes in matter and energy chemists , physicists and engineers are examples of people who work in physical 30 A This is experimenting with lasers . The Study of Matter and Energy Physical science is the study of matter . energy . and the changes they undergo . Matter is all around you . It is anything that has and tI ' space . is the ability to do work or cause change . Branches of Physical Science ' is into two main and . Chemistry is study of tho of and how mutter . When you study . you will about , that nuke up mid why dill of matter have properties . You will out how matter can and wit ) ou why ( I i , do nut . Physics is study of . motion , and . and how they interact . When you study you will learn about the different forms of energy and the physical laws that . You ill also out how tho ul pit ) apply to . solar , and ( hi universe . All of the prop shown in Figure work in an ol ic il . Sumo ( carton , such as , i ' piano tuning . or , i you . ing that , is only it you work in like these . But you use physical science all the time . For ple . when you blow on a spoonful to cool it down . you using ( book , you will more ' involving physical .

Target Reading Skill Preview Text Structure Reviewing Key Concepts A Two engineers are installing communications equipment on a mountaintop . Big Ideas of Physical Science Physical scientists apply ( i big ideas in their work . As you this book , you will begin to grasp that help to unify physical sciences force and energy the laws of conservation atoms . and the theory the behavior of of matter in solids . liquids , and gases . Th big . ris that will be required ' you continue lu . lo out how ' apply lo you and the world around you ! What is physics ! Section Assessment the ni ' lor this ( lion . How did you your question about The Miner and ?

I . I . Listing shill ' us to learn more about the natural world . Comparing and Contrasting How do and inferring differ ?

Classifying or an ?

raining . Explain . Defining What is physical ?

Identifying What are the two of ?

Inferring How would a of be . to ?

To a . Reading Quantitative or Qualitative ?

Look around your room at home . Write down three qualitative and three quantitative . How do these two types of observations from one another ?

Chapter ! Plan and conduct a ic investigation to test a hypothesis Distinguish between able and controlled Parameters in a test . How do scientists investigate the natural world ?

What role do models , theories . and laws play in ( Key Terms I scientific inquiry I hypothesis ' parameter I manipulated variable I responding variable I experiment I data I communicating model I scientific theory I scientific law A shadow puppet Scientific Inquiry Can You Make a Shadow Disappear ?

Using a piece of clay as a base , set up a straw so that it stands up straight . Shine a flashlight on the straw from as many directions as you can Observe the different shadows you ( Record your observations . Determine whether you can make the shadow disappear while using the light . If you can . describe how you did it . Think Over Posing Questions If you had a meter stick among your materials , what are two other questions you could investigate ?

you ever puppets uti wall ?

are when blocks light shining on surface . Making shadow might make you wonder about light mid . Your curiosity can his the first step in iL inquiry . inquiry to ways scientists study the natural world . It is the ongoing process ) cry in . lust like , that is the tint step in inquiry . have other habits oi mind as well , lu . and . me reporting truthfully . is ( new and ' Skepticism is about ! up with new ways to strive . The Process of Inquiry inquiry duct nut occur in the same tray . But . certain arc . The processes that scientists use in inquiry include posing questions , developing hypotheses . designing experiments . collecting and interpreting data , drawing conclusions , and communicating ideas and results . Figure shows some of this ways that processes can happen .

Route The Nature of Inquiry Then is no set path that a inquiry must follow . Different scientists may choose paths when studying the same even Communicate a Hypothesis . Draw Conclusions . Collect and Interpret Data Posing Questions Suppose you want to iearn more about light and shadows . You might ask , Does the sin of a shadow depend on the distance Go between the light and the object ?

How is at shadow affected by ' the position ?

Will you get shadows if you have several mum ?

For The Nature ul Inquiry activity All those questions about light and shadows are vim . questions because you can answer them by making Web tions . For example . by observing the shadow of at tree over eral hours during the day . you can see how the shadow changes with the sun position . Not all questions are scientific , however . For example , pose you ask . Which is the most interesting photo in contest ?

The answer to that question is based on personal opinion . not on evidence . inquiry can not answer questions based on opinions . values , or judgments . Whit questions an you ask about light and shadows ?

911 variable FIGURE Investigating Shadow The photo shows an experiment designed to test two variable , the distance between an ub ?

I and a light sauna , and the size ! the shadow . Interpreting Diagrams Wharf the variable ( the distance between light and object Developing Hypotheses inquiry when ideas can he tested For example , you want in find out how the distance the and the light i ( the we of a . Your lint step might he develop it . A hypothesis is possible ' to ( it ( question or fur a set of . For ' say ( the ! mi light the size the ul ' It i ) tu that yuur hypothesis is not . lead to that can he tested A he by or experiment . In that . can he ( that nut support the ) trials are ' can be as ti ue . Designing an Experiment You can a by an ) I . The lint an ment in all the . parameter is that an be measured in an . called vai ' ate the ones that change during the . In ment . one ) in ) the manipulated variable . The vai Ir that is to change of the manipulated is the variable . at . experiment , the the the light and the . The responding is the height of the . To he sun that in the variable are the in the . keep all the uther is . kept constant . Figure shows that need In in your the type oflight . the height and angle if the light . and the distance the and the Wall . Art ii in which unly one is at it time is Responding . high , of shadow a controlled experiment . It ad . What a hypothesis ?

Distance Between Height of Object and Light ( Shadow ( 34 10 32 32 IS 27 so 20 25 23 25 13 i ' 16 30 22 24 35 21 no 20 zo . Foam Showing Experimental Results 20 30 50 the results of the shadow experiment are shown here as a data table and as a graph . Interpreting ) Graphs What do the data show ?

Distance Between Object and Light ( Collecting and Interpreting Data begin an experiment . they . mile table for recording data . Data arc . and other ( A data provides an way to and record observations . it data table that you might made during your shadow experiment . Recall that can he or . Data can he ur . can recorded as mile in ur lug . data consist at . Notice that measurements in data in ) it unit of length . the data are collected . they to he lud , Graphs are a way to data they can reveal trends or patterns in the data . look all in . It ) that as tho distance the object and the light increased . the height of the Li . You can learn abuut using data and graphs in the Skills . How do scientists collect data ?

. 11 . I i Yhe Work of A Model This is a of the scalar blue represent the by the pianist sun Drawing Conclusions Alter . they 11 their . A ( 111 not . in . 11111 1111111111 ( i . hi 11 ) Communicating An ' and through and . also . the process med 111 111111 ' 11 the ! can . that ' In Lil ( hy . 111 in . 111 iL ( and ' with . How Science Develops Uver the . the world . 11111 than collect facts , I . i ' tor use models and develop theories and laws to people of the natural world . Scientific Models , 11 111111 ' 111 ub ' Su ) 11 is . 111 ' iL ' 111 11 ' by , il of ( he or how , 1111 , uh . such ax ' that 11111111 up 111 , haw hem ' up ut . What is a model ?

Scientific Theories In some crises . many can be ted by one explanation . This can lead to the development of theory . A theory is for at wide range of or results . For example , to the atomic theory . substances are composed of tiny particles culled atoms . The atomic theory helps explain ni ) such as why water or boils at certain temperatures . and why it can many other . Scientists accept theory only when there is large body of evidence that supports it . future may not support the theory . that happens . may ' the theory or discard it altogether , Scientific Laws Have you ever heard say , What goes up must come ?

When scientists observe the same result in circumstances , they may develop it ( law . law is statement that scientists expect to happen every time under it set of conditions . describes an observed pattern in nature without tin in ex lain it . You can think of a law as at mile . For the law . uw A ( to the law of gravity , stiles that objects in the universe attract each other . hi paya ( his law has been verified over and over again . land Assessment Vocabulary Academic words In an experiment . why you keep , At Home Activity Reviewing Key concepts Whith Falls Fastest ?

Design an . i i ' i . experiment to determine which falls . processes that are often involved in fa ( molded ghee of pap , lUU a sheet of paper folded in fourths . Inferring . How can experiment that di pi ' i or ( rumpled sheet of paper 89 ' sure to develop a hypothesis , design ' a . Defining ' is scientific theory ?

scientific law ?

a experiment , and collect . and Contrasting How do data . 00 your data support your theories laws ?

hypothesis ?

Discuss your results with . Classifying who ( the ' a family member . length Li that their results supported their hypothesis . fan their supported be called ?

Why or why not ?

Nit Students density is MOSS Students know how lo Der unit volume . the density substances ( regular and irregular solids and liquids ) from measurements at mass Why and volume do scientists use a standard measurement system ?

What are the SI units of measure for length . mass . volume , density , time . and temperature ?

Key Terms I weight ' MESS I volume I meniscus I density I Celsius scale I Kelvin Scale I absolute zero 160 In tasks such as cooking . measurements can be critical to success ! Measurement which Has More Mass ?

Your teacher will provide you with some small objects . Look at the objects , but do not touch them . which object is lightest . which is second lightest , and so on . Record your predictions . Use a balance to find the mass of each object . Based on the masses , list the objects from lightest to heaviest . Think It over Drawing Conclusions How did your predictions compare with your results ?

Are bigger objects always heavier than smaller objects ?

Do objects of the same size always have the same mass ?

Why or why not ?

Did ever ask a relative an family ?

If so . the answer might have been . the right amount of flour and wali si spoonful of oil El pinch of . Bake it for awhile until it limits just right . Instructions like these he difticult follow How much is the right ?

How big is a a pinch ?

You could end up with disastrous .

Common SI Prefixes Symbol Meaning 100 da hem de ( one tenth ) OCH ( one hundredth ) 0001 ( one thousandth ) A Standard Measurement System The recipe illustrates the ) using at of measurement . This is especially true in science . Using the wine of ' among all over world . More than 200 years ago . countries their own . Sometimes ( ur mom used in country . In ( in France developed a universal of called the . is i ul ' on the number ( scientists use an expanded system called the of . as ! for the French , i , all over the use 51 units to measure length . volume . muss , and time . Using SI as the standard system of measurement allows scientists to compare data and with each other about results . In this book . you will use SI and other metric units . Figure ti lists the used to name the most SI units may haw thew ' in units or kilograms . Because SI units arc ) a an pics at 10 , you can from one unit to . Fur example , I met equals centimeters You can learn about converting between SI units in the Skills . SI units are based on multiples of what number ?

Haul SI , based on multiples of are easy to use . Knowing what the prefixes mean ( an help you judge how big or small a measurement is . How much large ! in than a 17 Common Conversions Length for Length How far can you throw a softball ?

Can you estimate by eye how far the ball travels ?

A better way to find out would be to sure the distance . or length , that the ball travels . Length is the distance from one point to another . In the case of your softball throw , it would be from the point where you release the ball to the point where it first hits the ground . of Length The basic unit of length in SI is the meter ( In ) One meter is about the distance from the to a doorknob . A softball throw would be measured in meters . 50 would your height . Most students your age are between and meters tall . Science and History Measurement Systems Like so much else in science . systems of measurement developed gradually over time in different parts of the world , units of Merchants Mediterranean used be and 25 and a Mina was about 900 minted the first true coins to have standard weight and value .

To measure smaller than a meter , scientists use units called the ( or the ( The ( the prefix means . One meter , then , is equal In 100 centimeters or . length oi a typical is 18 . which is equal In 280 . What unit would you use to a long distance . such the distance two ?

For such . use a unit known as the kilometer ( The thousand There are meters in a kilometer . 399 ?

to draw a straight line San Francisco and ' Boston . the line would measure about kilometers . people use different ment units for other purposes . Research the units used in ing , horse breeding , diamond cutting , farming . or another activity that you . Write a few paragraphs about ) 789 Standard Units of Length and Weight The foot of Charlemagne . emperor of most of Europe . was set as the standard unit of length . The standard unit of weight was the . translated as Charlemagne ) 953 Standards The international Bureau of Weights and Measures in France I single set of standard units . Scientists world use these units in their work . The official kilogram measure , shown above . It kept a vacuum chamber . your findings .

Freon Measuring Length To measure the length of the turtle shell , lune up on end of the with the zero mark on the ruler Read the number at the other end of the to length . VIM I I 10 11 12 14 15 16 13 I ! 209 Measuring Length A very common tool used In length is metric you can ' a metric ruler is into . The arc the , and un . is unto arc marked by the shorter lines . To it . unc ' up with mark . number at the cud The shell of the Ill is ( or 88 . lung . One is divided into how many ' millimeters ?

weight and Mass you want tu nIL your wright . Tu lind the , you step scale like the one shown in Figure ID . Your body weight on the . you weigh . the , causing the on the scale tu turn further . giving higher . However . your smile would not the sum if you it In 111 munn and on it . on . of the would nut he as by your weight . How tan your weight it the amount of your body stays the mine ?

10 Measuring Weight You can stand on a state to measure your body .

Weight Your weight is at measure of the fora of gravity on you . Weight is measured in units such as or pounds . The newton ( is an 51 unit . If you weigh 90 pounds , your weight in Si units in about 400 . On Earth . all ' are attracted toward the center of the planet by the force of Earth gravity . On another planet . the force of gravity on you may be more or less than it is on Earth . On the moon , you would weigh only about All your weight on Earth . Mass Why do you weigh less the moon than on Earth ?

The of gravity depends partly on the mass of an object . Mass is a the amount uf matter an contains . If you travel to the moon , the amount of matter in your boil ) ur not change . But . the mass of the moon is much less than the mass of , so the moon exerts much less gravitational force on you . Unlike weight . mass docs Common Conversions not with location . even when force on an ' object . For this reason scientists prefer to matter by its mass rather than its weight . woo Units of Mass The SI unit of must the kilogram ( If you weigh 90 pounds on Earth , your mass is about 40 grams . Although you will see kilograms used in this textbook . usually you will see a smaller gram ( There are grams in a kilogram . A nickel has a mass of grams , and ti has a grams . 11 Measuring Mess A measures mass in he grams . How do you a mass in grams to the equivalent mass 355 in kilograms ?

Hint Look at the table . 350 A pineapple has a mass of about or . An average orange a mass of about 230 or .

hour 12 Measuring Volume Volume is the amount of space an object takes up . Measuring the volume of liquids , rectangular solids , and irregular solids requires different methods . Observing What is the proper way to read a meniscus ?

Common Conversions for Volume , Rectangular Solid To calculate the volume at a rectangular solid , multiply length width height . To measure the volume of a liquid . read the level It the bottom of the meniscus . or curve . Volume ) you drink or orange juice with breakfast ?

if so . how much do you have ?

You probably don ! measure it out you inst pour it into glass . You decide when to stop pouring by observing the amount of space it in the glass . Volume is the amount of space an object takes up . Units of Volume Common units of volume include the cubic meter , the liter ( the milliliter ( and the cubic centimeter ( The 51 unit of volume is the cubic meter ( However . the volumes you measure in the lab will be much less than I cubic meter . So , you will it easier to express volumes in liters , milliliters , or cubic centimeters . A is equal to the volume of a who that measures on catch side . You have probably seen and bottles of beverages at the grocery store . You can measure smaller volumes in milliliters . A milliliter is one of a liter . and is exactly the same volume as I cubic centimeter . A of water has a volume of about milliliters . An ordinary can of soda contains 355 milliliters of liquid . Volume of You can use a graduated to measure liquid . The graduated cylinder in Figure is marked oil in segments . Notice that the top surface of the water in the graduated cylinder is curved . This curve is called a meniscus . To determine the volume of the water , you should read the milliliter marking at the bottom of the meniscus .

Solids To measure the volume of an irregular solid . use the displacement method . Record the volume of water in the cylinder . place the Irregular solid lnto . the water . Record the volume of the water plus the . the volume at the water alone from the volume all the water plus the object . of How can you determine the volume of a cereal box ?

Volumes of rectangular solids or are often given in cubic centimeters . A cubic centimeter is equal to the volume of cube that measures centimeter on each side . This is about the sin of sugar cube . You can calculate the volume of a rectangular object by using this Volume Length Height . Area Because the area of a rectangle equals length width , another way to write this is Volume Area Height . Suppose that at cereal box is 20 centimeters long . meters wide , and 25 centimeters high . The volume of the box is Volume ( I Area Height Measurements always have units . So . when you multiply the three measurements . you must remember to multiply the units ( the numbers ( 20 25 ) Volume of Irregular Solids How can you measure the ume of an irregular object . such as a piece of fruit or a rock ?

One ' way is to submerge the object in water in a graduated cylinder . The water level will rise by an amount that is equal to the volume of the object in milliliters . This method is shown in Figure . 23 Fast 13 Comparing Densities Although the bowling ball and beach ball have the same volume , one contains much more mass than the other . Inferring Which item has the greater density ?

What is the density of a wood block with a mass of 57 and a volume of 125 ( What is the density of a liquid with a mass of 45 and a volume of 48 ?

Density As you can see in Figure 13 , two objects of the saute size can have very different masses . This is because materials have different densities . Density is mass per unit volume . To calm the density of an object , divide its mass by its volume . Units of Density Because density equals mass divided by volume . the units for density combine the units of those two measurements . The Si unit of density is the kilogram per cubic meter ( in this textbook . you will often see expressed in grams per cubic centimeter ) fur solids and grams per milliliter . for liquids . In each case , the is a measure of mass . and the denominator is measure of . Reviewing Math Number Sense ) Calculating Density Suppose that a metal object has a mass of and a volume of 21 ( Calculate its density . Read and Understand What are you given ?

Mass object 57 Volume of metal object 21 Plan and Solve hat quantity are you trying to calculate ?

The density of the metal object What formula the given quantities and the unknown quantity ?

ii ' Volume the calculation . Mass 579 Density Vow , 11 , Look Back and Check Does your answer make sense ?

The answer tells you that the metal object has density of , The answer makes sense because it is the same as the density of a known .

Densities of Common Substances The table in Figure lists the densities of some substances . The density of substance is the same for all samples of that substance . For ple . all of pure matter how large or a density of . you know an density , you can predict whether the object will or sink in given liquid . If the is less dense than the liquid , it will . object is more dense than the liquid . it will sink . For example . is I . A piece of wood with density of will in water . A ring made of pure silver . which has a density of gum , will sink . Densities of Some Common Substances . Will an with density of or ' my , The density of a substance stays the same no matter how large or small a sample of the substance Time is . Applying Concepts How could . rod ' The crowd cheers wildly as you near the line . lou push , ae , your legs to run even faster in the moments of the race . gold ?

From the corner ofyour eye . you see your opponent catching up to you . At like this . just one second can mean the dill winning and losing . Units of Time ( The second ( is the SI . Your heart beats about once per you are not ning . than is ! The second can easily be divided by multiple of IO . like the other SI units . For example . a millisecond is of LI second . Longer periods of time are ' in minutes or hours . There are on in 21 minute , and 60 minut ' in an hour . Measuring Time You use clocks and watches to time . Some digital Stopwatches . which are used to time . can measure time accurately In one hundredth ofa second . 15 Measuring Time You ( an use a to measure time Common Conversions for Time 25

Celsius ( Kelvin ( Temperature As you head out the door each morning , one of the first things you might notice is the temperature . is it cold out this morning ?

How high will the temperature rise ?

Boiling Point oi Watt ! Units of Temperature Scientists commonly use the Celsius scale . On Celsius Scale , water freezes at and boils at There are exactly degrees between the zing point and boiling point of water . Normal human body ' is about . in addition to the Celsius scale , also use another temperature scale . called the Kelvin scale . Units on the ( scale are the same sir as those on the Celsius scale . The ( is the SI unit of temperature . The temperature ( i on the Kelvin scale is called absolute . Nothing can get titan this ture . Absolute zero is equal to ' on the Celsius scale . Freezing Point at Water Measuring Temperature You can measure lure using . consist of a scaled tube that contains it liquid . The liquid expands or contracts as the temperature changes . Absolute Zero ! 16 we the Celsius and Kelvin scales to measure temperature . Section Assessment ' Target Reading Preview Text structure I ) Estimating baseball Complete the for this section , bat and mass of baseball in SI units . What question did you ask about Weight and can you check am ?

Man ?

What was your answer ?

Describing 41 method MINT for the density baseball . Reviewing Key Concepts mu ' Identifying What the . system by scientists around the world ?

Predicting Suppose that two different measurement systems in their work . Two solid cubes have the some mass . They each have a mass of 50 arm if my . Calculating Density tube A has a volume of dam ?

an . What is its density ?

a . Listing What am the Si . Density Cube has a volume oi . A ( What is its density ?

Making Sense of Density . Problem Does the density of a material vary with volume ?

Skills Focus drawing conclusions , measuring . controlling variables Materials I balance I water I paper towels I metric ruler I graduated cylinder , I wooden stick , about long I ball oi modeling clay , about wide I crayon with paper removed Procedure . Use a balance to find the mass of the wooden stick . Record the mass in a data table like the one shown above right . Add enough water to a graduated cylinder so that the stick can be completely merged . Measure the initial volume of the water . Place the stick in the graduated cylinder . Measure the new volume of the water . The volume of the stick is the difference between the water levels in Steps and . Calculate this volume and record it . The density of the stid equals its mass divided by its volume . Calculate and record its density . Thoroughly dry the stick with a paper towel . Then break the into two pieces Repeat Steps through with one piece . Then , repeat Steps through with the other piece . Repeat Steps through using the clay rolled into a rope . Repeat using the crayon . PE ?

Volume ' iii Density Object ( Wooden Fear Modeling clay Woo I Piece whoa Piece Piece i Analyze and conclude . Measuring For each object you tested . pare the density of the whole object with the densities of the pieces of the object . Drawing Conclusions Use your results to explain how density can be used to identify a material . Variables Why did you dry the objects in Step ?

Communicating Write a paragraph explain ing how you would the procedure to obtain more data . Tell how having more data would affect your answers to Questions and above . Design an Experiment Design an experiment you could use to mine the density of olive oil . With your permission , carry out your plan . Use the library or the Internet to find the actual density of olive Oil . Compare your experimental value with the actual value . and explain why they may differ .

Science and Should the United States Go Metric ?

On long car ever , Arc we there yet ?

If the driver answered . We 30 kilometers away , would you know whether you were close to your destination or far away ?

As a US . resident . you probably have no trouble understanding English units , which include miles , feet , pounds , and gallons . Metric units , however . maybe more unfamiliar . But most countries in the world use the metric system . Should the United States convert to metric or continue using the English system ?

Why Change ?

People III the United States are with the English system at . country convened to metric . might have time products or . These may not disappear . BU ) in the United ' rel ) un the English . Many of the and that goods are based the English system . are the goods . go metric . machine would have In he and the goods . This gould cost millions . ans ) METRIC SYSTEM

Why Not Change ?

Supporters of the metric ) point out how easy II is . metric an based the lit , from to . is . to feel , or gallons to , is . cuuld master much more ( the English . may help the United State stay in foreign trade . Many LES . businesses sell their in . But in units they know in this . metric units . They may avoid products that are not made to metric . In fact . mild in Europa must be labeled in metric units only . The countries in red ( use the English system of measurement . You ec i de Why Not Compromise ?

The next time drink a bottle ofjuice . look at its label . likely , it both English and that are a cum . allow of both to know what they are buying . Sum that such an well enough . People who need to use the metric . as in ) be able use it . However . those who prefer to me English units he lu ( in so as . Identify the Problem In your own words . state the of converting to the system . Analyze the Options Du tin ( that have recently gone . it did countries farce ?

Huw did they ?

Did the convening to system the ?

Find a Solution a stance on this in a class about whether or not the United States save on a to the system . Support your opinion ' with facts from this feature and mum . Go Online ion More on going metric Visit unt DINING , Web Section Evaluate the and reproducibility of data . what math skills do ( use in collecting data and making measurements ?

Key Terms I estimate I accuracy I I ( I . For Links on math and science Visit Welt Code 300 Integrating Mathematics Mathematics and Science How Many Marbles Are There ?

Yourteacher will give you a of marbles . With a partner , came up with a way to determine the number of marbles in the without actually counting all ol them . Use your method to determine the number of marbles . Write down your answer . Compare the method you used to that at another group . Think It Over Predicting which method do you think led to a more answer Why ?

What are same tools that scientists use ?

You might think of ' and ( are aim that you lind All a ) Curiosity , ci attitudes that guru iii inquiry . is tool , of knowledge that is particularly useful in the study of ence in . is for asking and about world . Estimation Have you ever been on stage and haw there were in the audience ?

Maybe you counted the number of people in one row and by the of . This would lac um win to at all . An estimate is ill of a number based on i ' Estimating is nut the 115 ' an estimate is bawd un . Scientists must sometimes rely on when they can not obtain exact numbers . fur . can ! measure the distance between stars . An might an indirect . tions , and .

Accuracy and Reproducibility Suppose you were to meet at friend at . Your friend at and says . But it according to all the clocks in my The problem is that your clocks do not show the accurate . or correct , time . Accuracy refers to how close a is to the true or actual value . An accurate clock would read ' Your friends clocks may be working properly , but because they are set 15 minutes late . they are always inaccurate . Reproducibility What would happen if you never told your friend that he was late ?

Your friend would always be late by IS minutes . if the two of you tried to meet at . on consecutive days , your friend would arrive at each day . Your friend clocks may be inaccurate . but when used for repeated measurements . they yield consistent results . The times measured with your Friend clocks can be said to be reproducible . Reproducibility refers to how close a group of arc to each other . Accuracy and reproducibility do not mean the same thing . To help you understand the . think about a game of darts . As Figure shows . accurate throws land close to the . Reproducible throws , on the other hand . land close to one another . Your friend clocks show times that are reproducible hut inaccurate . like the arrangement of darts in the middle dartboard . Accuracy and Reproducibility in Suppose you want to measure your friend height . The needs to be accurate . or close to your actual height . The measurement also needs to be . This means that if you measured your friend height several times . you would get the same measurement again and again . Scientists aim for both accuracy and ity in their measurements . To ensure accuracy . you need to make your carefully using the ate instruments . To ensure reproducibility . you need to repeat the a few times . Mort ! 17 Accuracy and Reproducibility In a game of darts . easy to see the difference between accurate throws and reproducible throws . In order to hit the consistently . you need both accuracy and A Both Ind arrow 31

If I am certain of Ihe ' bul am estimating the . Therefore . my measurement , can be expressed to only significant figures , From 18 Figures A measurement should contain only those numbers that are significant . Measuring Why can you report the length of the we to only two figures ?

Area To find the area at a surface , multiply its length by its width . Suppose a sheet of paper measures 215 by . Area Practice Problem What is the area of a ticket stub that measures by ?

I I I I Significant Figures and Precision Figure shows a tile next to a ruler marked off in meter segments . Suppose you measure the length of the tile as 53 centimeters . This has two that are . The in a measurement include all of the digits that have been measured exactly . plus one digit whose value has been estimated . In measuring the tile to be centimeters long . you are certain of the , but you have estimated the . So . the measurement centimeters has two . What if the ruler had been marked in ments ?

You would be able to make a more precise measurement . Precision is a measure of the exactness of a measurement . With a more precise ruler . you might measure the length of the tile as centimeters . The measurement centimeters ( three ) is more precise than centimeters ( two ) Scientists use figures to express precision in their measurements and calculations . Adding or Subtracting When you add or subtract ments . the answer should have the same number of decimal places as the measurement with the least number of decimal places . For example , suppose you add a tile that is meters long to row of tiles that is centimeters long . decimal place ) decimal places ) an ( decimal place ) In this calculation . the measurement with the least number of decimal places is centimeters ( one decimal place ) So the answer . centimeters . should be written to only one decimal place . The correct answer has three . What are ?

lulu ?

tut Multiplying or Dividing When multiplying or dividing measurements . the answer should have the same number oi figures as the measurement with the least number of significant figures . Suppose you need to tile a space that sures meters by meters . The calculated area would be ( significant ) figure ) mi ( significant figure ) The answer has one the ment with the last number meters ) has one . length in has three , while the width ' in has one . Therefore , my answer can have only one . 19 Multiplying When you measurements . your answer can have only the same number of figures as the measurement with the fewest figures . section Assessment Vocabulary Skill Academic Words is the meaning oi the in the term ?

Reviewing Key Concepts Identifying What math skill do scientists rely on when exact ) How can you be sure that your measurements are accurate and ?

Interpreting Data Using a metric ruler with millimeter friend measures the width of book to be . How many digits can you be certain oi ?

055 . Area To win a prize at a fair . you must throw a coin into a space that is long and wide . What is the area of the space you are aiming for ?

Express your answer to the correct number at figures Focus the slope of ( lit linear graph as the constant in the relationship to and apply this in interpreting graphs lrom data . Distinguish between linear and nonlinear relationships on a graph of data What type of data can line graphs display ?

How do you determine a of hest hi or the slope of a graph ! Why are line graphs powerful tools In science Key Terms I graph I horizontal axis I vertical I origin I coordinate I data point I line or best fit I linear graph I slope I nonlinear graph 340 Graphs in Science Standards What in a Picture ?

I . Read over the information written below . At age . Sarah was 75 tall . By she turned , Sarah had grown 10 . By age , she had grown another 10 . At age , Sarah was 100 tall . Look at the picture below . Think it Over Inferring What are the advantages of showing information in a visual way , rather than with words In paragraph form ?

What trend do you see in the picture ?

a long day and all you can think about is food . You toss down your gym bag and head into the kitchen . Now for some pasta ! it if water on ' turn on the haul . and wait eagerly for the water to . minutes . you are still waiting for first sign of . the saying A watched pot never really be true ?

is the water taking longer to boil today hecause you put than usual ?

volume to boiling time ?

You could do an and collect sonic data to out .

The Importance of Graphs In Section you learned why it is important tu organ ?

the data you collect in an experiment . at table is one way to experimental data . Another way to show data is in the form of a graph . You can think a graph as ture of your data . Have ever heard the saying , A picture is a thousand words ?

This is exactly why graphs are such useful tools . Because of their visual nature , graphs can reveal patterns or trends that words and data tables can not . The three types of graphs that scientists commonly use are bar graphs . circle graphs . and line graphs . You can learn about graphs in the Skills Handbook . This section focuses on line to create them and how to pret the patterns they reveal . Collecting Data . I in an Why Are Line Graphs Useful ?

Suppose you set up the ' an experiment in Figure 20 . You record in at data table the time it mum am and plot a line graph takes each pot of waiter to boil . From your data table , you can to see the relationship between tell that as the volume of water . the boiling time ' Inferring Why might a line graph seems to increase as well . But a line graph could reveal more be more dam ?

clearly how these two variables are related . Line graphs are used to display data to show how one variable ( the responding variable ) changes in response to another variable ( the manipulated variable ) In the experiment . the responding variable is the time it takes for the water to boil . The manipulated variable is the volume of miter in the put . Data Table Volume ( Bolling Time 500 min 48 ( min ) 16 min 57 ( min ) 26 min 00 ( min ) min 44 ( min )

Data Table ?

Water ( min ) 500 Plotting I Line Graph When should you plot a line graph ?

The answer is . when your manipulated variable is that is . when there are other points between the ones that you tested . In the experiment , volumes of . 502 , and so on exist between 500 and Time and mass are other continuous variables . To plot a line graph of your data , follow these steps . or . line that runs left to right . The vertical axis . or . is the line that runs up and down . Label the axes . label the axis with the name of the manipulated variable . Label the vertical axis with the name of the responding variable . Be sure to include units of on each axis . Create I scale . On each axis , create a scale by marking oft intervals that cover the range of values you will show . Both scales should begin at um when possible . The point where the two axes cross is called the origin of the graph . On this graph . the origin has coordinates of ) which milliliters and minutes . A coordinate is a pair of numbers used to determine the position ofa point on a graph . Plot the data . Plot a point for each piece of data . The ted lines show how to plot your piece of data ( 500 . Follow an imaginary vertical line extending up from the axis at the 500 mark . Then follow an imaginary horizontal line extending across from the vertical axis at the minutes mark . Plot point where these two lines cross . or intersect . The point showing the location of that intersection is called a data point . Draw a of best A line of best lit is a smooth line that reflects the general pattern of a graph . Though your first instinct might be to simply connect all the clots . that not the correct approach to drawing a line graph . Rather , you should first stop and look at the points you plotted to identify a eral trend in the data . Then draw a smooth line between the points to that general pattern . Notice that the resulting line of best fit for this graph is a straight line . A line graph in which the data points yield a straight line is called a linear graph . Add a title . The title should identify the variables or shown in the graph . I What it I data point !

11 Go Plotting a Line Graph Vou can a picture af data by following these six steps . I ! Web Code Draw the Axes Plot the Data nis Draw a Une of Best Fit III 500 , FIGURE 21 Drawing a Una at Best For this graph , a line going up tram left to right the data more than a zigzag does . Relating Cause and Effect What ( anal might explain why the data points don fail perfectly along a straight line ?

Why Draw a Line of Best Fit ?

You he wondering . with lint line graph . why this is , the situation . your thu experiment as you did and in 12 . that your friend graph shows the same general trend as going upwards from left to right . if yuur simply ( the , linc he , I ' than straight line . Why do your friend data points tall perfectly along line ?

It ix ' data is ( and can introduced . By simply dots . you would place too much lance on data point in the shape of the line . A line of best fit the overall trend shown by all the data as a whole . Why should you automatically connect the ' I dots when creating a line graph ?

rig Time of Water by Volume the dots incurred and may be . Drawing i at best is the wly to reflect the trend in the data Bolling Time ( min ) Tips for Drawing a Line of Best Fit . I if the data points , a straight line , draw a ( I Include as data points as on , For data points . do . easily an Iin ' try to nave th amt number of points above the line as below line . 389

Reviewing Math Algebra and Functions I Distance Traveled Over Time Data Car Travel The graph shows the distance a car travels in a period . Use the graph to answer the questions below . Reading Graphs What variable is plotted on the horizontal axis ?

The vertical axis ?

Interpreting Data How tar does the ( ar travel in the first 10 minutes ?

In 40 minutes ?

Predicting Use the graph to predict how far the ear would travel in 120 minutes . Assume the car continues to travel at the same speed . Calculating Calculate the slope of the graph . What information does the slope provide ?

20 30 40 50 ( min ) Slope When a line graph is linear . can determine a value called slope . One way to slope is the steepness of the graph line . OThe slope of a graph line tells you how much changes for every change in ' I Run , To calculate slope , pick any two points on the line and write GUI ! 23 down the coordinates . In Figure 13 , suppose you chose the points ( 20 . 10 ) and ( 50 . 25 . The slope of a line indicates how much changes for every change 25 10 . 15 I in When the ' slope of this line ?

20 min in min In the case of Figure 23 , the slope represents the distance the car per unit of time , or its speed . So the speed of the car is . Note that the speed is constant . On linear graph . the slope is constant . If the straight line of linear graph goes through the origin ( the graph can be expressed as the following equation Distance Over Time In this equation . is the manipulated variable . is the responding variable . and the constant is the slope . Look again at Figure 23 . Substituting for the variables ( time ) and I ( you can now write Distance ( I )

24 Trends In Graphs Data may yield one at the trends shown in these graphs . leading Graphs Which graph shows no relationship between the two variables ?

400 Linear Trend As the distance Baskets and Distance Population Growth 3838 Bacterial Calls 00 20 40 60 Time ( min ) Nonlinear Trend by dividing in two I I ) from the hoop increases . the number of basket made every 20 minutes . The number decreases . The graph line of bacterial cells increases sharply . descends to the right . The graph is a steep curve . Using Graphs to Identify Trends Your data won always give you a graph with a straight line . A line graph in which the data points do not fall along it straight line is called a nonlinear graph . Whether a graph is linear or nonlinear . the information it contains is very useful . Line graphs are powerful tools in science because they allow you to identify trends and make predictions . linear When graph is linear . you can easily see how two variables are related . For instance . Graph A in Figure 24 shows that the one student stands from a basketball hoop . the fewer baskets she can nuke . You can also use the graph to make predictions . For example , how many baskets can she make at distance of meters ?

you extend the graph line . you can see that your would be one basket . Nonlinear Trends There are several kinds of nonlinear graphs . In some nonlinear graphs , the data points may fall along at curve . A curve may be shallow , or it may be steep , as in Graph . Other nonlinear graphs show different trends . A graph may rise and then level off , as in Graph Or . a graph may show a repeating pattern . as in Graph Because each of these graphs reveals a trend in the data . they are useful in understanding how the variables are related . What is a nonlinear graph ?

Distance Ill ( an 02468101214 00 30 45 so oJ . lune tan June Time ( min ) Month Age ( years ) Trend On a bike Nonlinear Trend In many No Trend The amount of ride . the distance you hike places , rainfall varies with the vision children watch and their increases with time . it you stop seasons . The graph shows a ages are not related . The data to rest , the distance remains the repeating , or cyclical , pattern , points are scattered , and the graph same and the graph levels off . shows no recognizable pattern . No Trend In other nonlinear graphs . the data points may be about in no recognizable pattern , as in Graph Would you be surprised to learn that even such graphs are useful ?

When there are no trends in at graph , it most likely means that there is no relationship the two variables . Assessment Section Target Reading Preview Text Structure the graphic organizer for this section . What question did you ask about ?

What was your ?

Reviewing Key Concepts I . I . Reviewing What can graphs reveal that data can not ?

Describing What can a line graph tell you about the relationship the variables El HINT in an ?

Interpreting Data Could you usea line graph HINT El scientists to do . and Din Figure 24 . to show data how body mass ( the responding variable ) changes with ( the variable ?

Explain . Defining What is a line of best lit ?

Explaining What docs calculating the slope of a graph line tell you about the data ?

Comparing and Contrasting How docs a graph line with a steeper slope compare to one with is slope ?

Reading up . Listing List two things that line graphs allow . Reading Graphs Describe how Graphs A Which Line Is lest ?

Show a family member how to draw a line of best fit by plotting the data points lrom Figure 22 onto a piece of graph paper . Tape the graph paper onto a thick piece of cardboard . Insert a into each data point . Then arrange a piece of string so that it best reflects the data . Once you have determined the line of best fit . tape the string to the graph Explain why a line of best fit need not go through each data point . on lie .

Density Graphs Problem How can you determine the density of a liquid ?

Skills Focus graphing . calculating Materials graduated cylinder balance graph paper sample volumes of the same liquid Procedure . Measure the mass of an empty graduated cylinder . Record the mass in a data table . Pour one of the liquid samples into the cylinder . Measure and record the mass of the graduated cylinder plus the liquid . Calculate the mass of the liquid alone by tracting the mass of the empty graduated cylinder from the mass in Step . Determine the volume of the liquid by ing the level at the bottom of the meniscus . Repeat Steps 24 with the two other samples . Analyze and Conclude . Graphing Use the data in your data table to create a graph . Graph volume on the axis ( and mass on the vertical axis ( Interpreting Data Look at the points you plotted to identify a general trend in the data . Then draw a line of best fit that reflects Go . i For Data Visit Web Code . Calculating Select two points on the graph line and calculate the slope of the line . I sh Run . Drawing Conclusions Repeat Step using a different pair of points on the graph line . Compare the two values calculated for the slope . What does the slope represent ?

Communicating Explain why mass and ume measurements lor any sample at the uid should fall along the graph line , Design an Experiment Propose a plan to determine which is more marble . a plastic spoon . or the liquid used in this lab . Obtain your teacher permission the trend in the data . before carrying out your investigation . Oat Table Mass of Empty Mass of Liquid Of of Simple Graduated and Graduated Luigi MOM Lana Cylinder Cylinder A

Science Laboratory Safety progress is made by Where ' the safety Equipment in asking questions and YOU ?

i ' Look around your classroom or school for any equipment . Draw a plan of the room or building Sta Fa Why is preparation when carrying out . ind he and clearly label where eath item is located . Think It Over What should you do ii an Why is it important to know where ( equipment is ( ated ' you and your family lu gu ruck . What plans should you ?

need to bring . some to eat , and water to drink But you also need lo plan for everyone safety . For the climb to ) want lo make sure that Im the proper clothing and ) gear . such as mers . harnesses . and climbing shoes . ou check to see whether the is in good condition You also want In than proper and their role as take their climbing . Flaunt 15 Climbing Safely Climbing rocks safely requires ( preparation and the use ol proper equipment ,

' am ' Fur Links un safety Wei Code I FIN ! 26 Safety in the tab Good preparation for an experiment helps you stay in the laboratory ( in three precautions each student taking while performing the labs re had long hair to keep it away from flames , chemicals . or equipment , i Wear plastic gloves to I protect your skin when handling . 440 Safety in the Lab lust as when yuu gu , you have to be . you begin any . Good preparation helps you stay safe doing science activities in the laboratory . and an 501116 of the yuu will use in labs . Do you know how to use these items ?

What should you do if something goes wrong ?

Thinking about questions ahead of time is an important part of being . Preparing for the Lab for lab should begin the day you will the lab . It is important In mid and stand all the directions . Also , review the general lines in including tu ( equipment you will use . If , is unclear . he prepared to ask yuur about it you lab . i Wear safety goggles to protect your from splashes . glass breakage , and sharp objects . i Wear an apron to protect yourself and your clothes i from chemicals .

Performing the Lab Whenever you perform a science lab . your chief must he safety of yourself . your malm , and your . most important ) is ple Always your instruction and he textbook directions . You should on your own without asking your teacher tint . labs and activities in this scrim safely hula like right . These ' you to dangers in the lab and remind you In . also any safely equipment that you should use in pfUI ( rum hazards . Thu arc in detail in Appendix you are with each symbol and what it . Another thing you can do to make your Lib safe and successful is to keep your work ' clean and organized . clu nul rush any uf the . Finally , show and In your and . I Id . What Is the man important rule ?

Wear gloves when handling hal objects . Keep your work area clean and . Make sure electric cords are mangled and out of the way . Wear shoes when working in the laboratory . Safety Symbols ?

Safety Lab Apron Gloves Plastic Gloves Healing No Flames Corrosive ( FUMES Sharp Object Animal Plant Safety Electric Shock Physical Safety Disposal Hand Washing General Awareness From 17 in the field These students are collecting data outdoors . Applying Concepts What sa precautions should they keep in mind while performing their activity ?

469 Procedures Your lab work not when you reach the last step in the procedure . There are important things you need to do at end of every lab . When you have completed a lab . be sure to clean up your work area . Turn off and unplug any and return it to its proper place . is important that you dispose of any waste materials properly . should not be thrown in the trash or poured down drain . Follow your teachers instructions about proper disposal . Finally . he sure to wash your hands thoroughly after working in the laboratory . Safety in the Field The laboratory is not the only where you will conduct investigations . Some investigations will be done in . The can be any outdoor . such as a yard , a forest , park . or a . lust as in the laboratory . good preparation helps you stay safe when doing science activities in the . There can be many potential safety outdoors , For example , you could ' weather . traffic , wild mails . or poisonous plants . planning may help you avoid some potential hazards . For example . you can listen to the weather and plan your trip accordingly . ards may be to anticipate . Whenever you do work , always tell an you will be carry out a field . Ask an adult or a classmate to accompany you . Dress for the weather and other conditions you will encounter . Usc common ( to avoid any dangerous situations . What are some potential outdoor hazards ?

In Case of an Accident Good preparation and careful work habits can go a long way toward making your lab sale mics . But . at some point . an accident may occur . A might accidentally knock over a beaker or chemical might spill on your sleeve . Would you know what to do ?

my occurs , no matter how minor . notify your teacher . Then . listen to your teacher directions and carry them out quickly . Make sure you know the location and proper use of all the equipment in your lab room . Knowing safety and first aid procedures beforehand will prepare you to handle . 28 lists some procedures you should know . FIGURE 28 Tips These tips can help guide your actions during emergency situations . Remember , always notify your teacher immediately if an occurs . Section Vocabulary Skill Academic Words What shuuld you do alter you complete a laboratory activity ?

Make list with at least steps . Use the term in the title of your list Reviewing Key if a . Listing List two things you should do ahead of time to prepare for ( I lab . Interpreting Diagrams Suppose it lab included safety symbols below . What do these mean ?

What precautions should you talc ?

Making Generalizations Why is it more lu prepare for a luh activity in the field titan for one in a laboratory ?

365 St In Case of Emergency ALWAYS NOTIFY TEACHER 100 What to Do immerse burns in i Cold water . Burns Cuts Cover cuts with a clean Apply direct pressure to the wound TOD bleeding . Flush the skin with sh amounts of ' Flush the . with large ' amounts of water . 599 medical attention . up . it ding . Writing an I ! I . Reviewing Suppose lah activity you get it cut and start to is the first thing you shuuld do ?

Sequencing Outline in order the next steps ' I ' you would to deal with your injury . Making Judgments Some people feel that most accidents that occur really could have been with better preparation or . Do you agree or disagree with this viewpoint ?

Explain your reasoning . Writing in Science safety rules in Appendix A to post inyour lab . Be sure to include the safety symbol . dear directions , and additional illustrations .

Chapter What Is Physical Science ?

Key ( use the skill ) Anti Iu lI world . I ' iu the study of and . and . Key Terms ' i ( predicting ic Inquiry Key ( a . used in inquiry include posing , collecting , and interpreting data , drawing . and communicating . usc and and theories to increase under of world . Key Terms inquiry data hypothesis parameter model theory ) it . law . Key Concepts , Using SI allows ( to dam and communicate with each other about . SI units in . and Volume Area Height . Mass ) Volume Key Terms SI volume ( Kelvin mass density absolute Zero 480 Study Guide Investigate the natural world by posing questions . developing hypotheses . designing experiments . dau . Ind communicating results Mathematics and Science Key . and making . scientist use math skills . and . Key Graphs in Science Key Concepts . Line graphs are to data to we how one ( III ' i . in to another . figure precision I A lint 01 but lil . shown by all the data taken as A whole . Rise Run , Slope Lin graphs are in may allow you lu identify trends and malt ( Key Terms graph data point line of heat graph origin lope nonlinear graph Science Laboratory Safety Key I Good preparation helps you stay safe when doing in th or . When any ' cu ma . no how . notify your earlier ' listen ' directions and carry uut .

Review and Assessment Go . Whiz For ( Visit ( Web ( ode in ) Target Reading Skill . Preview Text Structure . of the . Then . i ammo ! I ! graphic I ! i and . Ind How do Reproducibility differ from reproducibility ?

Significant Figures and Precision Revie Key terms Choose the letter of the best answer . A I ' from prior experience is called ' prediction . an . an Ub . Ii In an experiment when you temp . is the . hypothesis . The of malt an its a . truss . weight . Repeated measurements that are close to one ' Il . Am . inquiry . In the that it glass breaks during ii In a . your hands . it . up the broken glass . yum . Complete the following sentences so that your answers clearly explain the key terms . a predicts the weather . she makes . A key in th sci is collection ni data . which are . You turn predict ' will in water ii you know the density . is . The . centimeters has three , hich menu that ' 10 . One way in ii graph is to I the slope . which tells . Writing in Science Interview You are a sports reporter interviewing an Olympic swimmer who lost the silver medal try a few hundredth of a second . Write a interview in which you discuss the meaning of time and the advanced instruments used to measure time . Saul The Work of Scientists Gunter ! 49

Review and Assessment Concepts 11 . In ) own . is . 12 . Why must testable ?

13 . In A . why is it ( inc variable II time ?

14 . Why must scientists tut ( units ( it in their ?

15 . is it to be both accurate and ?

16 . When graphing . why should you draw a line that the general pattern . than simply points ?

17 . I is ! three things you can do prepare . thinking Critically 18 . Comparing and Contrasting objects ) has a greater volume ?

Explain . Arm um 19 Applying , EC this and your explain why ice cubes float in 20 . Relating Cause and Effect . many measurements and , and lab through . in the end , you til 50 percent . what may have led to such high percent error . 11 . Making Judgments yuu think that . is at al ) mu ! never bring food or drink intoa ?

Ma 21 . Calculating Density A of water . Practice 23 . Area arca til that 17 till . 12 . Applying Skills Use the graph to answer Questions . a law over minutes . Volcanic Lava Flaw Distance ( Time ( min ) 20 . Reading Graphs is plotted un the ?

Th ' 25 . Interpreting Data Did the stream travel the same minute ?

26 . Predict the ' Standards Investigation Performance Assessment ofyour while building vour . I ) most part ) ship ) were easiest ?

and system . and describe its .

Standards Practice Choose the letter of the best answer . I . the length of several times as . and . The actual length is . Which best describes A The measurements were accurate . I The measurements were not accurate . but they were reproducible . The measurements were both accurate and reproducible . The measurements were neither accurate nor reproducible . A sample has a mass of and a volume of . What is the density of sulfur ?

A I 72 The graph below shows the masses of five different volumes of liquid . Use the graph and your knowledge of science to answer Question . Mass and Volume oi Liquid . What is the slope ofthe graph line ?

A . I Success is Tro Orin at the graph below compares how well two different brands of Insulated mugs retain heat . Each mug was with the same volume of boiling water . Use the graph and your knowledge of science to answer Questions . Comparing Insulated Mugs Temperature ( 00 90 70 60 ) 40 30 20 10 time ( minutes ) Which in this experiment was the variable ?

A the temperature til the water the location of the insulated mug the brand of insulated mug the length of time the water was allowed to coal . What can yuu draw from this experiment ?

A There is no difference between Brand A and Brand . Brand A keeps water warmer than Brand . Brand keeps water Wanner than A . seems to add heat to the water . Suppose are given a sample of at liquid . How can yuu predict the ula much larger sample of the same liquid ?

Describe the measurements and calculations required to make yuur prediction . as