Focus on California 8th Grade Physical Science Textbook Chapter 3 Solids, Liquids, and Gases

Chapter Solids , Liquids , and Gases ' Standards Preview Elm oi the more than 100 has distinct and a All of matter If ! composed of one or more or me As a baa lor under standing this content know the slates or matter . gas ) depend on ma . mallow Students know that In Ihe atoms are closely locked in Damon and ( an only atoms and are mare loosely ( and ( an collide with and move past one another . and an gave ) the alarm and ma ! are free to mow ( an processes in atom are rearranged into ent molecules A I basis Inc this corrupt know processes and , In which a no ( i nude by question and investigations A I bash lor And addressing the cement In the other . students should develop own and . Students will the a ( and ( data graphs ham dam and state menu I relationships Between . mound wring , water exists as a , and gas 849

or . the BIG Ide How do solids , liquids , and gases differ in the motion . of their particles ?

Check What You Know Suppose you leave a towel out on the beach on a hot , sunny day . After a few hours , you return to get the towel . How would the temperature of the towel have changed ?

Chapter ! as The Images shown here represent some at the key in this chapter . Vou can use this vocabulary skill to help you understand the meaning of some key in this chapter . A Is a letter or group ol letters added to the end of a word to ( hange Its meaning and often Its part of speech For example , the suffix ! ion added to a verb can form a noun that means process of or action prepare preparation process of the motes of preparing In chapter , you WI learn key terms that end In the , and sI on . Suffix Meaning Part of Key State of , Vaporization , evaporation , of , an of , I State process Surface tension of , act of Apply It ! Vapor is another word for gas . Use the chart above to predict the meaning of vaporization , your as needed . When you come across an unfamiliar word . look at the suffix to help you determine the meaning . Then cheek the in the glossary or a dictionary .

Chapter Vocabulary Section amorphous tension Section vaporization evaporation pressure ( inversely ( Build Vocabulary On In Visit ) Web Code 1030 Chapter to Reads Create Outlines An outline shows the relationship between main ideas and details An is set up like the one below . Roman numerals show the main topics or headings Capital letters Show the . show supporting details and key terms . Look at the sample outline ol the his part 01 Section . of Matter A . Particles In a Solid Solids A Locked in and can only vibrate Solids hue and volume Main . of Solids , a . Particles form ai repeating . Examples salt . snow solids nut . in a regular pattern glans . rubber , plastic . A . Particles in a Apply It ! What are the main topics in this . What details Support Types of Solids ?

Copy the above your notebook , Use the headings , and key terms to help you select to complete the outline for Section . Create an outline A Story of Changing States thus chapter , you learn how of matter change from a to a to a gas . As you read ( you a model that shows these changes Your Goal To ( a slut or cartoon that demonstrates how of matter behave as they change horn a to a to a gas and then from a gas to a to a To the investigation , you must what happens to the each change of state I outline your or an a storyboard format your cartoon or produce your skit Plan It ! group of classmates , a Inst of the of minds , and gases You ' be working on this as you study . when you , the motion of particles in . and gases , and begin a storyboard . Add when you Section and complete your cartoon or skit at the and the ( Finally , present your completed or cartoon to the class .

Standards Focus Students know that in solids the atoms are closely locked in position and can only vibrate in liquids the atoms and molecules are more loosely connected and can with and move past one another , and in gases the atoms and molecules are tree to move independently , colliding How ( all you describe the motion ol particles In a solid ?

How an you the motion of particles in a liquid ?

How can you describe the motion of particles in a gas ?

Key Terms solid ' crystalline solid amorphous solid I liquid I fluid surface tension viscosity I gas haunt I Water as a Solid Ice , or water in solid form . a great for skating , Observing What useful property does the frozen water have here ?

NO States of Matter Standards What Are Solids , Liquids , and Gases ?

Break an antacid tablet ( fizzing type ) into or four pieces . Place them inside a large , uninflated balloon . Fill a plastic bottle about hallway with water . Stretch the mouth of the balloon over the top of the bottle , taking care to keep the tablet pieces inside the balloon . Jiggle the balloon so that the pieces fall into the bottle . Observe what happens for about two minutes . Remove the balloon and examine its contents . Think It Over Forming Operational Definitions Identity examples ot the different states of , liquids , and you observed in this activity . Define eath of the three states in your own words . What are the speed skaters in Figure I on ?

You bly But you may also answered . So which is the right ?

In . both answers are correct . to the stance that makes up the skating compound with the chemical formula . Depending on the and pressure . water can as zi solid . liquid . or gas . Ice waiter . ur water in wild .

' lull bu , ur . 111111111011 the sun and stars , but not ' 1111 , 11 ' liquids , 11111 ) the is . ul . 113 ( list ( them 15 mun , liquids . Solids What it you 111 up as pen , 11 mun plan to ' I ' 111 ' mu 111111111 il ?

pen put it in howl ?

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Hi 11111 . solid . and ' 11 . then 11 will keep and volume in any 1111111111111 and . Haunt Liquid lava . Solid Rodi , lava flow . a when a semi , new . rmed , View of a Solid Particles of a solid vibrate bad and forth but are closely lacked in position . Types of Solids are either crystalline or amorphous . Online For Links on Visit Web Code 91 Particles in a Solid The particles in a solid are packed very closely together . In addition , each particle is tightly fixed in one position . This . closely arrangement causes solid to have a shape and volume . Do the particles that make up solid ' at all ?

Yes , but not much . The particles in st solid are closely locked in position and can only vibrate . This means that the particles move back and forth slightly . like a group of people running in place . In a solid . the have enough energy to vibrate . but not enough to slide past one another . Types of Solids In many solids , the particles form a regular . repeating pattern . create crystals . Solids that are made up of crystals are called crystalline solids ( KRIS tuh lin . Salt , sugar . and snow are examples ul crystalline solids . When a solid is heated . it melts at a . amorphous solids ( uh ) particles arc not arranged in a regular pattern . and glass are amorphous solids . Unlike 21 crystalline solid . an . solid docs not melt at a distinct temperature . Instead . it mil ) become softer and softer or change into other . How do crystalline and amorphous solids , Quartz is a crystalline solid . Its particles are arranged in a regular pattern . not arranged in a regular pattern .

Liquids A liquid ha a volume but no shape of its own . Without a container . at liquid spreads into it wide . shallow puddle . Like a solid , however . a liquid does have a vol ume . Suppose you have milliliters of liquid in a ated cylinder , as shown in Figure . If you pour the liquid into a flask , you still have milliliters . The liquid has the same volume no matter what shape its commuter has . Particles in in Liquid In general . the particles in a liquid are packed almost as closely as in a solid . However , the in a liquid move freely . Compared to particle in solid . the particles in liquid are more loosely connected and can collide with and move past one another . As a result . a liquid and has no shape . A liquid is an example of . meaning a substance that You am compare the movement of particles in a liquid to the way you might mow a group of around in your hand Like the particles of a liquid . the marbles slide around one another but stay in contact . In solid or liquid form , the atoms of a substance stay at about the same average distance . 50 the of the liquid remains very close to that of the solid . from Equivalent Volumes A liquid takes the shape of its container but its volume does not ( hange . 100 Particle View of a liquid Particles in a liquid are packed close together , but can collide and move past one another . allowing liquids to flow . and Contrasting How are liquids and alike ?

How do they differ ?

FIGURE Surface Tension Water heads up on a leaf due to attractions between the water molecules Surface tension in water is strong enough to support the weight of an insect Try sAc ity As Thick as Honey You can compare the of two liquids . Place on a table a clear plastic jar full of honey and another clear plastic jar quarters full of vegetable . Make sure that the tops of both jars are tightly closed . Turn the jars upside down at the same time . Observe what happens . Turn the two jars up and again watch what happens Drawing Conclusions Which fluid has a greater viscosity ?

In which liquid do you think the particles are more loosely con ?

940 Properties of Liquids ( inc is tension . Surface tension is the result of an inward pull the molecules of liquid that the on the closer together . Perhaps you have noticed that and can head up un many . such in Figure . That because water attract one another strongly . cause zit the water to be pulled slightly the ' molecules beneath the surface . Duc . of water can act lilac it sort of skin . Fur , a ' when you place it gently on the surface of at glass ol . but it quickly sinks it you push it the surface . Surface tension the insect in Figure to the calm surface of pond . is viscosity ( vis ( uh it liquid ' to flowing . A liquid on the size and of its and the the particles . Some liquids more easily than Liquids with high vi , Hunt ' an of liquid with ly high viscosity . Liquids with low ' quickly . Water and vinegar low . what property of liquids causes water to term , droplets ?

target Reading Skill Create In your Reviewing Key Concepts Gases Like a liquid , gas is a . Unlike a liquid , however , a ya can change volume very easily . if you put a gas in a closed . the gas particles will either spread apart or be together as they that container . Take a deep breath . Your chest expands . and your lungs with air . Air is a mixture of gases . When you breathe in , air moves from your nose to your windpipe to your lungs . in each place . the air has a different shape . When you breathe out . the changes happen in . If you could see the particles that make up a gas . you would see them moving in all in Figure . As they move . gas particles spread apart , all the space available . Thus . a gas has neither shape nor volume . Compared to particles in a liquid , the particles in a gas have more energy of motion . gases , the atoms and molecules are free to move independently , colliding frequently . The distance between particles in a gas is much larger than the between particles in a solid or a liquid . You will read more about the behavior of gases in Section . Section Assess notebook , your outline for Section I . What supporting details did you include under Properties oi Liquids ?

Defining What is a solid ?

Describing How can the motion of particles in a solid be described ?

Comparing and Contrasting How do crystalline solids differ from amorphous solids ?

Describing How may liquids be described in terms of shape and volume ?

It . Explaining How do the positions and of particles in liquid help to explain the shape and volume of the liquid ?

Relating Cause and Effect Explain why a sewing needle can on the surface of water in a glass . a . Describing How can the motion in a gas be described ?

Reviewing What determines the shape and volume of a gas inside a container ?

Applying Contents Use what you know about the particles in a gas to explain why a gas has no shape or volume . oil I Particle View of a Gas Gas particles move about and randomly with the walls at a container and with each other . Predicting What will happen if the container Is removed ?

Liquids and Gan Show your family haw liquids and gases . Fill the bulb and cylinder of a turkey water . Seal the end with your finger and hold it over the sink . Have a family member squeeze the bulb . Now empty the turkey baster . Again , seal the end with your finger and have a family member squeeze the bulb . Did the person notice any difference ?

Use what you know about liquids and gases to explain your observations . Gupta ! Standards Focus add Students know the states of matter ( solid , liquid , gas ) depend on molecular motion . Students know physical pro include and boiling , in which a material changes form with no reaction , What happens to a substance during changes between solid and liquid ?

What happens to a substance during changes between liquid and gas ?

What happens to a substance during changes between solid and gas ?

Key Terms melting melting point freezing I evaporation boiling boiling point I condensation sublimation 960 Changes of State , Standards What Happens When You Breathe on a Mirror ?

Obtain a hand mirror . Clean it with a dry cloth , Describe the mirrors surface . Hold the mirror about 15 away from your face . Try to breathe against the mirror surface . Reduce the distance until breathing on . the mirror produces a visible change . Record what you observe , Think it Over Developing Hypotheses What did you observe when you breathed on the mirror held close to your mouth ! How can you explain that ?

Why did you get different results when the mirror was at greater distances from your face ?

Picture an ice on hot summer . The ice quickly starts to drip onto your not surprised . You that ice if it not cold . But why tho ice cream mull ?

Particles of ' at a ' more energy than of that same substance it a cooler ' You that ' I Il clingy always as lIt from it warmer substance to a cooler substance . So , when you take ice cream on i summer day . it absorbs energy trom the air and your hand The energy changes this ice main ) from i solid in il liquid . Increased thermal turns on , ice cream cone into a gooey mess !

Solid silver Liquid silver Changes Between Solid and Liquid Particles of a liquid have more thermal energy than particles of the sattle ' in solid form . As a gas . the pa have even more thermal energy . So . at from solid to liquid an in energy . A from liquid to solid is lust the It involves At ( lee in thermal energy . in energy ' it change in . States of depend on . For any , the ul motion of its particles solids to to gases . Resisting this motion are of attraction particles . The balance between the particles motions and attractive threes determines the slate of matter . Melting The ( hange in state from it tu liquid is called melting . In most pure . melting ) at it called the melting point . The melting point rat pure water is tI ( I . lite melting point rut table salt ( Note that melting point changes with air pressure . When a substance melts , the in the solid vibrate so fast that they break free from their positions . Think ice cube taken from the freezer . The energy In melt the ice mostly trom the air in the room . At tirst . the added thermal energy the average molecular motion of the water . The molecules . and the temperature of the ice increases . But at . the temperature of the ice . Any ( energy alum the water break out of their positions in crystals and to collide with one mother . The ice melts into liquid water . Haunt to Liquid In solid silver , the atoms are in a regular . cubic pattern The atoms in liquid ( molten ) silver have no regular arrangement Applying Concepts How can a jewelry maker take advantage of in the state Chapter 097

Liquid to Solid Just a few hours in a freezer will change water into a solid . Activity Keeping Cool . Wrap the bulbs of two alcohol thermometers with equal amounts of gauze , thermometers on a paper towel on a table . Use a medicine dropper to put to drops of water on the gauze surrounding the bulb of one thermometer . Using rubbing alcohol rather than water , repeat step with the second thermometer . Read the temperatures on the two thermometers for several minutes . Data Which liquid evaporates faster ?

Explain your answer . Freezing The change from a liquid to a solid is called freezing . It is just the reverse of melting . When a substance freeze the particles in the liquid move so slowly that they begin to take on fixed positions . Suppose you put liquid water into a . The water loses energy to the cold air in the . The water molecules move more slowly as they lose energy . The dom of motion of the molecules decreases . Over time , the water becomes solid . When water begins to treat . its temperature remains at until is complete . The freezing point of water . is the same as its melting point . Note that both melting and freezing are reversible physical changes . They are not changes . Liquid water that is still water . Likewise , ice that melts is still water . ical can usually be undone to recover the original materials unchanged . For example . after melting an ice cube . you can freeze the liquid water to recover the original solid . 42 What happens to the particles at a as they lose more and more energy ! Changes Between Liquid and Gas Have you ever wondered how clouds or how puddles dry up after a rain shower ?

To answer these . you need to look at the changes that occur between liquid and gas states . The change from a liquid to it gas is called vaporization ( vay ih shun ) takes place when the particles in a liquid gain enough energy to move independently , forming gas . As a changes from liquid to gas . the relative of motion of its atoms or molecules . are two main types of ' evaporation and boiling

Evaporation that takes place only on the face of a liquid is tailed evaporation ea uh RAY shun ) A shrinking puddle is an example . Water in the puddle gains energy front the ground , the air , or the sun . added energy enables some of the water molecules on the surface of the to escape into the evaporate . Bolling Have you ever watched a pot of water boiling on a stove ?

Boiling occurs when a liquid changes to a gas below its surface as well as at the surface . When water boils . vaporized water molecules farm bubbles below the surface . The bubbles rise and eventually break the surface of the liquid . The temperature at which a liquid boils is called its boiling point . The boiling point of a substance depends on the sure of the air above it . The lower the pressure . the less energy needed for the particles of the liquid to escape into the air . In places close to sea level . the boiling point of water is . In the mountains , however , the air pressure is lower . and so is the boiling point of water . in Denver . Colorado , where the tion is meters above sea level . water boils at . Boiling point is a characteristic property of a substance . Evaporation During eva . water vaporize only at the . For Links on a ! state Visit Wei ( ode more 11 Evaporation and Boiling Liquids ( an vaporize in two ways . Interpreting Diagrams How do these processes differ ?

Boiling During boiling , water vaporize both at the surface and within the liquid . vaporized water molecules form bubbles below the surface and . on Analyzing Data Temperature and Changes of State A beaker of ice at was slowly heated to . The graph shows how the temperature 01 the water changed overtime . Reading Graphs What two variables are plotted on the graph ?

Reading Graphs What is happening to the temperature of the water during segment of the graph ?

Interpreting Data What does the temperature value for segment represent ?

For segment ?

Drawing Conclusions What change of state is occurring during segment of the graph ! During segment ?

Reviewing Math Algebra and i Changes of State for Water no so I 81012141618 Yime ( minutes ) Inferring In which segment , A or do the water molecules have more energy ?

Explain your reasoning . 12 Condensation of Water Water vapor from a hot shower contacts the tool surface of a bathroom mirror and ( into liquid water . 1000 Condensation The ' lI is . Condensation i in from a gas to a liquid . You can tion by ( into at ' When warm ' vapor in your breath the cooler of the mirror . the water vapor condenses into liquid . During condensation . the particles in is gas lose enough thermal energy to form a liquid . The gas Ill ) the attractive forces among them . As i changes from gas to liquid . the relative ' of motion of its atoms or molecules decreases ( typically when water vapor in i i ) into liquid . When the droplet get heavy enough . they fall as rain . Note that water vapor is Al colorless gas that you can not see . The steam you set above a kettle of boiling i ' is not water ( I . neither are Clouds or log . What you we in those cases are tiny droplets of liquid water suspended in air . like thi changes solid and liquid . the liquid and gas are ri cal . When sul ) or . it with no ' For example . when water vapor condenses . the liquid that is still water .

Changes Between Solid and Gas if you live where the winters are cold , you may that snow seems to disappear even when the temperature stays well below . This change is the result of sublimation . Sublimation occurs when the surface particles of ti solid gain enough energy that they form ' gas . During sublimation . particles of at solid do not pass through the liquid state as they form I 3115 . As a solid substance into a gas . the relative freedom of motion ofits particles . One example of sublimation occurs with dry ice . Dry ice is the common name for solid carbon dioxide . ordinary atmospheric pressures . dioxide can not exist as a ii liquid . So instead of melting . solid carbon dioxide changes Dry Ice directly into gas . As it changes state . the carbon dioxide ?

94 absorbs thermal energy . If warmer are placed near . into a gas . Predicting it dry ice , they will lose thermal energy and become ( older . For you the , ya , this reason . dry ice can be used to things cold when a room temperature , refrigerator is not available . When dry ice becomes a gas , 59 ' it cools water vapor in the nearby air The water vapor then condenses into a liquid . forming fog around the dry ice . Rating What physical state is skipped during the ?

sublimation of a substance ?

Section Assessment Vocabulary ( the . Relating Cause and Effect Why does the using the correct word ( evaporation of sweat cool your body on a ! a put ( it water boils . the liquid will and form gas . toiling and evaporation . Identifying Whai mean as lulu I dry ice gradually get smaller ?

Reviewing Key concept , I ) Interpreting Photos What is the fog you see ' in the air around the dry ice in Figure I ?

a , Reviewing What particle rill a solid as it a liquid ?

lly does me form 11 , El ?

i ' trying In stay . Should you snow and then drink it , or just eat snow ?

pan . comp . he and a . Describing What is ?

oi peep muons . Comparing and Contrasting Name the of , in liquid and in rim types of . Tell how they are , similar and how they . 550 101 Melting Ce Problem How does the temperature 01 the surroundings affect the rate at which ice melts ?

Go Online min For Data sharing Web ( ode Skills Focus predicting , interpreting data , inferring Materials stopwatch or timer thermometer or temperature probe plastic cups , about 200 each stirring rods , preferably plastic I ice cubes , about on each side warm water , about ( I water at room temperature , about Procedure . Place one ice cube in each ( up . Begin timing with a stopwatch . Gently stir each cup with a stirring rod until the ice has completely melted . Observe both ice cubes carefully . At the moment one of the ice cubes is completely melted , record thetime and the temperature of the water in the cup . Wait for the second ice cube to melt . Record its melting time and the water temperature . Analyze and conclude . Predicting Was your prediction in Step sup . Read Steps . Based on your own ence . predict which ice cube will melt faster . In your notebook , make a data table like the one below . Fill a cup halfway with warm water ( about to ) Fill a second cup to the same depth with water at room temperature . Record the exact temperature of the water in each cup . If you are using a temperature probe . see your teacher for instructions . Obtain two ice cubes that are as close to the same size as possible . Data Table ported by the results of the experiment ?

Explain why or why not . Interpreting Data In which cup did the water temperature change the most ?

Explain . The ice absorbed energy as it melted . What was the source of that energy ?

How did the added energy affect the relative freedom of motion of the water molecules ?

Communicating Write a paragraph ing how errors in measurement could have affected your conclusions in this experiment . Tell what you would do differently if you repeated the procedure . Hint How well were you able to time the exact moment that each Ice cube completely melted ?

Time ?

When a lake freezes in winter , only the top turns . to ice . Design an experiment to model the I ing of a frozen lake during the spring . Obtain ' your teacher permission before carrying out your investigation . Be prepared to share your results with the class . Design an Experiment 10 !

Standards i ! Students know the states of matter . gas ) depend on molecular motion appropriate graphs from data and develop quantitative statements about the relationships between variables What types of measurements are when working with How are the volume . temperature , and pressure ui a gas related ?

Key Terms I pressure proportional I inversely proportional Before a . a balloon tilled with air . The Behavior of Gases Standards How ( an Air Keep Chalk From Breaking ?

Stand on a ( hair and drop a piece of chalk onto a hard floor . Observe what happens to the chalk . Wrap a second piece of chalk in wax paper or plastic food wrap , Drop the chalk from the same height used in Step . Observe the results . Wrap a third piece of chalk in plastic bubble wrap . Drop the chalk from the same height used in Step I . Observe the results . Think it Over Inferring Compare the results from Steps , and . What properties of the air in the bubble wrap accounted for the results in Step ?

do you prepare a for a ride ?

First . you the balloon . using . Then you heal the air with gas . For and its cargo in rise . the ' must he than the air outside the balloon . does this ?

How can you the through the ?

How can you make it come down when you are to land ?

To thew questions , you need in stand Ui ' the . pressure . and volume ol gas .

Measuring Gases much helium isin the tank in Figure 14 ?

lfyou the mass of the helium . measuring the of the give you the ?

expand . To fill the tank . helium was Ut pressed together its volume , When you use the helium . it total volume inflated greater than the the tank . I he resulting volume , depends the temperature and air pressure that day . hen working with a gas . it is helpful to know its volume , temperature . and pressure . 30 what exactly do these mean ?

Volume From Chapter I , you know that volume is the uf space that matter . Volume is in cubic ' liters ' aml other . Because gas is the same as the volume of its . Temperature Hut . cult ice packs , you arc with matter at different . But what does ture tell you ?

Recall that all and are . a ( of the average of at the particles at . The the particles are moving . tho greater their and the higher the . You might think ola as fur . Even at temperature . the speed at particle in it gas is very last . At about 20 , particles in gas travel about per than twice the cruising speed of let plane 14 How Much Helium ?

A helium tank the height of this girl ( an fill over 500 balloons Photos How is the helium in the tank different from the helium in the balloons ?

and till the spate . the ! at Pressure Gas particles constantly collide with one another and with the walls oftheir container . As a result . the gas pushes I on the walls of the container . The of the gas is the force of its outward push divided by the area of the walls of the container . Pressure is measured in units of ( Pa ) or kilopascals . Pa The ofa object comes from the pressure of the gas . For example . the air inside a fully pumped basketball has a higher pressure than the air outside . This higher pressure is due to in greater number uf gas particles per unit volume inside the ball than in the surrounding air . What would happen ifyou punctured a in the ball ?

Air would leak out of the ball through the hole . The sure inside the ball would decrease . and the hall would become softer . Why does the air inside the bull leak out , rather than the surrounding air into the ball ?

The higher pressure inside the ball results in gas particles hitting the inner surface of the hall more often . Therefore , gas particles inside the ball reach the hole and escape more often than gas particles outside the ball reach the hole and enter . Thus , many more particles go out than in . The pressure inside drops until it is equal in the pressure outside . what units are used to measure pressure ?

FIGURE 15 A Change in Pressure A basketball as the gas particles begin to escape . High Pressure Higher gas pressure Inside the hall keeps the bull . Higher number or gas particles per unit volume low Pressure As gas particles escape . pressure Inside the ball decreases . Under Pressure . Obtain a round . inflatable party balloon and a pushpin . the balloon and knot the end . Carefully prick a hole in the balloon with a pushpin . Observe what happens . Inferring Was the air pressure higher inside or outside the balloon ?

Why did the balloon deflate ?

Lower number of gas particles per unit volume ores A tied , balloon is at room temperature . FIGURE 16 a Balloon The volume of a balloon decreases as temperature decreases , and then increases as temperature . Fleur Law when the temperature 01 a gas increases at pressure , its volume increases . Inferring What happens to the gas particles ar the temperature increases 105 Higher temperature , greater volume Lower temperature , smaller volume The balloon is lowered into liquid nitrogen at . The balloon shrinks as 935 volume . Temperature and Volume Figure 16 shows what happens when a balloon is slowly lowered into liquid nitrogen at nearly . then removed . As the air inside the balloon cools . its volume decreases . When the air warms up again . its volume increases The pressure remains more or less constant because the air is in a container . Charles law French scientist Charles examined the relationship between the temperature and volume ol a gas that is kept at a constant pressure . measured the volume of gas at various temperatures in a container that could change volume . When the temperature of a gas is increased It pressure , its volume increases . When the temperature of a gas is decreased at constant pressure , its volume decreases . This principle is called Charles law . Now think again about balloon . Heating causes the air inside the balloon to expand . Some of the warm air leaves through the bottom opening of the balloon , keeping the pressure slant . But now the air inside is less dense than the air outside the balloon . so the balloon rises . the pilot allows the air in the balloon to cool , the happens . The air in the balloon contracts . and more air enters through the opening , The density of the air inside , and the balloon sinks .

The balloon is at room When removed from the temperature again . nitrogen , the gas and the balloon expands . Graphing Charles ?

Law Suppose you do an experiment to test Charles law . Figure 18 shows a gas contained in a der with a movable piston . The piston allows the gas to change volume at constant pressure . The experiment begins with 50 of the gas in an bath at . Then the water is slowly heated . Each time the temperature increases by the gas volume is recorded . Note that the temperatures in the data table have been converted into . the SI unit of ture . To convert from Celsius degrees to ( add 273 . Asyou can see in the graph . the data points yield a straight line . In fact , if you extended the line downward , it would pass through the origin . When graph of two is a straight line passing through the origin . the variables are said to be directly proportional to each other . The graph of law shows that the volume ofa gas is directly portional to its kelvin temperature under constant pressure . How do you convert from Celsius degrees to . is linear Trend As the water bath heats up . the gas inside the cylinder expands . the data show a linear trend . At constant pressure , the volume of a gas is directly proportional to its kelvin tern . Cylinder 80 10 60 50 40 . 20 Temperature ( animus

Pressure and Volume Suppose you use a bicycle pump to a tire . By pressing down on the plunger , you force the gas inside the pump through the rubber lube and out the ironic into the tire . What happens to the volume of air inside the pump cylinder as you push down on the plunger ?

What happens to the pressure ?

Boyle Law lit the the scientist Robert Boyle ducted experiments in an to improve air pumps . lle the volumes of gases at pressures . that gas and pressure re related . When the pressure of a gas at constant temperature is increased . the volume of the gas decreases . When the pressure is decreased . the volume increases . This relationship is called law . law applies to in which the gas is changed The pressure then changes in the opposite way . For example . as you push down on the plunger of ai bicycle pump . the volume of air inside the pump cylinder gets smaller . and the pressure inside the cylinder increases . The in pressure me air into the tire . I . A pump makes use of we example ol ui action , et , between the um , altitude balloons . which are used in the study of the . and pressure 01 a gas . Researchers fill the with only a small of the helium gas that the balloons can hold As a balloon rises through the atmosphere . the air pressure around it decreases and the balloon expands . If the balloon were fully at . it would burst before it got very high . FIGURE 20 Boyle Law As weights are added . the gas particles a smaller volume . the pressure increases Go Online Fur Gas laws activity Visit . Welt Code ( 4023 least pressure , Increasing pressure , Greatest pressure . greatest me decreasing volume least volume 10 !

Graphing Boyle Law Suppose you conduct an experiment to test Boyle law . Figure shows a gas in a cylinder with a movable piston . A gauge cates the pressure of the gas inside the cylinder . The begins with the volume of the gas at 300 . The pressure of the gas is 20 . Next . the piston is into the cylinder . making the gas volume smaller . The pressure of the gas is recorded after each change in volume . Temperature remains constant . In this experiment . the manipulated variable is ume . Figure volume is shown on the scale of the horizontal axis from to 300 . The responding variable is pressure . Pressure is shown on the scale of the vertical axis from to 120 . As you can see in the graph , the plotted points he on a curve . not a straight line . Notice that the curve slopes downward from left to right . It is steep at lower , but it less sleep as volume increases . you multiply the two variables at any point on the curve . you will find that the product does not change . 300 20 ! 14 Id I Id 100 . 30 Wu ' When the product of two variables is a constant . the variables are inversely proportional to each other . The graph for Boyle law shows that gas pressure is inversely proportional to volume at constant temperature . lull ! What is the manipulated variable in the experiment ?

21 Pressure and Gas Volume Pushing on the top of the piston decreases the volume of the gas . The pressure of the gas increases . What would happen if you pulled up on the piston ?

Fawn 11 The graph of the data horn Figure 21 shows a nonlinear trend . The gas pressure is inversely proportional to the volume when temperature is constant . Calculating If you the volume of the gas to 25 . what would its pressure be ?

Boyle Law 17 Volume ( one Gas at low temperature Flaunt 23 Temperature and Gas Pressure when a gas is heated . the particles move faster and collide more often with eath other and with the walls of their container . The pressure of the gas . Video Id Tri solids , and Gases Gas at high temperature High a Pressure and Temperature If you dropped a few grains of sand onto your hand , you would hardly feel them . But what if you were caught in a sandstorm ?

Ouch ! The sand grains fly around very fast . and they would sting if they hit you . The faster the grains travel . the harder they hit your skin . Although gas particles are much smaller than sand grains , a sandstorm is a good model for gas behavior . Like grains of sand in a . gas particles travel individually and at high speeds ( but randomly ) The Faster the gas particles move , the more frequently they collide with the walls of their container and the greater the force of the collisions . Increasing Temperature Raises Pressure Recall from Section that the higher the temperature of a substance . the faster its particles are moving . Now you can state a relationship between temperature and pressure . When the temperature of a gas at constant volume is increased . the pressure of the gas increases . When the temperature is decreased . the pressure of decreases . Constant volume means that the gas is in a closed , rigid container . Pressure and in Action Have you ever looked at the tires of an truck ?

Because the tires need to support a lot of weight , they are large , heavy , and . The inside volume of these tires does vary much . On long trips . especially in the summer . a tines can become very hot . As the temperature increases . so does the pressure of the air inside the tire . if the pressure becomes greater than the tire can hold , the tire will For this reason , truck drivers need to monitor and adjust tire pressure on long trips .

Math Algebra and Functions Analyzing Data Graphing Gas Behavior In an experiment , the temperature of it gas ( in ) at a ( volume was varied , Gas pressure ( in ) was measured after each 273 change in temperature , The data from the experiment are shown in the table . Graphing Use the data to make a line graph . Plot temperature on the horizontal axis with a Sale from 270 to 300 Plot pressure on the vertical axis with a sale from to 25 . I Pa Pa ) Interpreting Data What was the manipulated . Drawing Conclusions What happens to the variable in this experiment ?

pressure of a gas when temperature is . Interpreting Data What kind of trend do the ' a ?

data show ?

section As Target Reading Skill Create Outlines Review Applying Suppose it is um your on the Behavior uf ( i . What are before a big parade . and are in charge at three important ideas that you should the parade balloons . You just learned about gases ?

that the temperature will rise ( between . early morning and the time the parade starts . How will this affect the tray you Huw hi pressure ?

Inna the nut Describing Describe how the of gas particles are related to the pressure exerted by the gas . Relating cause and Why does ' pumping more air into a ) increase , the the ban , finding Graphs Look for graphs in your . Ines . Point out to min a . Reviewing How does Bo do law describe ' mag ?

me gas and members of your family which variable is the Mum , manipulated variable and which is the I . Explaining Explain why increasing the fa gum Then compare any line graphs you have found to the graphs in this section . which at your graphs show two variables that are directly proportional to each other ?

Do any show variables that are inversely proportioned ?

temperature of at gas in is closed , rigid causes the pressure in the container to . 111 It a Gas Problem How does the pressure you exert on a syringe affect the volume of the air inside It ?

Skills Focus graphing , predicting , interpreting data . drawing conclusions Materials strong plastic syringe ( with no needle ) at least capacity modeling clay books at weight Procedure . Make a data table in your notebook like the one below . Lift the plunger of the syringe as high as it will move without going off scale . The volume inside the syringe will then be as large as possible . airtight . Hold the syringe upright with the clay end on the table . With the help of a partner , place one book on top of the plunger . Steady the book carefully so it does not fall . With the book positioned on the plunger , read the volume shown by the plunger and record it in your data table . Predict what will happen as more books are placed on top of the plunger . Place another book on top of the first book resting on the plunger . Read the new volume and record it in your data table . one by one , place each of the remaining books on top of the plunger . After you add each book , record the volume of the syringe in your data table . Predict what will happen as books are removed from the plunger one by one . 10 . Remove the books one at a time . Record the volume of the syringe in . Seal the small opening of the syringe your data table after you remove with a piece of clay . The seal must be each book . Data Table Adding Books Removing Books Volume ( Volume ( 111

Analyze and conclude . Graphing Make a line graph of the data obtained from Steps . and . Show the number of books on the horizontal axis and the volume in cubic centimeters ( on the vertical axis . Title this Graph . Graphing Make a second line graph ( the data obtained from Step 10 . Title this Graph . Predicting Did the results you obtained support your predictions in Steps and ?

Explain . Interpreting Data ( Graph with Graph . How ( an you explain any in the two graphs ?

Drawing conclusions What does Graph tell you about how the volume of a gas changes with increasing pressure ?

Communicating Write a paragraph ing how the volume of the gas changed as books were added one by one . Base your explanation on what was happening to the gas particles in the syringe . Design an Experiment How could you use ice and warm water to show how the temperature and volume of a gas are related ?

Design an experiment to test the effect on the volume of a gas when you change its temperature . Obtain your teacher before carrying out your investigation . 11 ' Study Guide In solids . the particles vibrate Iii closely patted . positions . In liquids . the particles are connected and with one another . in gases , the particles are free move independently . States of Matter The Behavior of Gases Key Concepts am Key Concepts . as Thu a arr I with a gas , Ii helpful to iii and um onlv vibrate . to particles in a solid . the particles the of a gas is at in a or trim ' and can constant . with and trim past . the tile gas at lI ) LIlL ' are free to ' the it I llI ) temperature ' volume ofthe gas . decreased . the ) Key Terms solid I When the iii i . is . the pressure iii the gas . When the in , fluid , gas ( i ! Key Terms ' directly i Changes of State inversely pi Key ( particles in the fast that they break free their . in liquid move ' that they begin In take fixed , talus ( ruin In ' forming , it gin . Volume ( nil ) During . in il ) thermal lu form ( liquid . ion zoo zoo 400 iii melting point reeling ) i hailing Temperature (

' Target Reading Skill ! El Go YURI . For . Visit ! nIn Web Review and Assessment Create Outlines Review ( Sum . In your ) the A Me . II important ' supporting ideas should you know ahout melting and ?

Oranges Between Solid and Liquid . Freezing I . Changes Between Liquid and Gas A . Evaporation Reviewing Key Terms Choose the letter of the best answer . A ) with but no Complete the following so that your answers clearly explain the key terms . A A . are ol ' which are ab . solid . til property ( I . solids aml liquids . gas will is melting point , which . keep in DI . keep its shape in ) A 01 15 El . to Full In it . Vi , have its volume decrease when the ' ind art two at mes . at . The in which A gas and 10 Al ' A quid I and us pressure are , sublimation . hailing . The gas is the farce of its outward ) hi the volume of its mass of its ( area of the walls of in . mass gas . Exploration Write an introduction to a safety manual for divers who use compressed air ( scuba ) tanks . Explain what air pressure is and what happens to gas molecules when air is compressed . Under constant ' the its are ' equal . not . Saul Solids . Liquids , and Gates 115

Review and Assessment Checking Concepts . 12 . 13 . 15 . 16 . 17 . 18 Thinking Critically 19 . 10 . 21 the ot particle in are and gases called ?

and contrast with high and law . How is the ' related In its stale ?

in . What to water when water is ( to I ?

to the particles when the an hall mil ?

How does ii iii rigid . its ?

Relating Cause and Effect why placing at dented lull in boiling miter is mic ( dent in the lull . the hall has no Applying Concepts you ( air ( the solid slowly lush mam and . this ?

interpreting Data Use the table that ) and pI ' til gas to how uf ' look . can the the two ' Volume ) Pressure ( 15 222 31 50 67 Applying Skills Use the table to answer Questions . mils ' lli ' in I 00 . tit ( its of Hit ' is in . Use ( I ' Temperature ( 37 47 20 56 30 66 40 22 . Graphing each axis ( graph with the appropriate . units , range of . Thun plot the in line graph . 23 Interpreting Data ' dues the . til the that will ( in water ?

It Predicting the ) in ( the ' is heated . Predict many grams will at ( Standards Investigation Assessment . I the to the ( hiss ( the illustrations . prepared a skit . the shit in hunt the . your . invite the ) to ask .

Standards Practice Choose the letter of the best answer . I . A wet towel is hanging on it clothesline in the sun . The towel dries the process ul A boiling . condensation . evaporation . sublimation . Which of the following correctly describes a gas ?

A The particles do not move . I The particles are closely locked in position and can only . The particles are free to move independently . colliding frequently . The particles are closely packed but have enough energy to slide past one another . Which state of matter has both volume and shape ?

A solid I liquid an plasma . As water vapor condenses into liquid water . the relative freedom of motion of the water molecules A increases . I decreases . stays the same . drops to urn because the particles are no longer moving . A gas at constant temperature is to at with a movable piston . The piston is slowly pushed into the cylinder , decreasing the volume of the pressure increases . What are the variables in this experiment ?

A temperature and time I time and volume volume and pressure pressure and temperature Success it Tracker Orin at The graph below shows changes In of a crystalline solid as it absorbs energy at I constant rate . Use the graph to answer Questions . so so so 120150 210 . Based on the graph . what is the total amount of energy absorbed by the substance as it changes from solid at to a gas ?

A 30 60 120 . What is the melting point of the substance ?

A 80 . Spray cans with gas usually have a warning printed on their that say , Store in a cool place . Explain the danger in storing the can near a source of heat . the motion of the gas molecules in the can when they gain thermal energy . 117