glencoe: new york scienceearth’s atmosphere, shown in figure 1,is a thin layer of air that forms a...

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sections 1 Earth’s Atmosphere Lab Evaluating Sunscreens 2 Energy Transfer in the Atmosphere 3 Air Movement Lab The Heat is On Virtual Lab What is the structure of Earth’s atmosphere? Fresh mountain air? On top of Mt. Everest the air is a bit thin. Without breathing equipment, an average person quickly would become dizzy, then unconscious, and eventually would die. In this chapter you’ll learn what makes the atmosphere at high altitudes different from the atmosphere we are used to. Write a short article describing how you might prepare to climb Mt. Everest. Science Journal Atmosphere PS 2.1a: Nearly all the atmosphere is confined to a thin shell surrounding Earth. The atmosphere is a mixture of gases. The atmosphere is stratified into layers, each having distinct properties. Nearly all weather occurs in the lowest layer of the atmosphere. 4.1a: The Sun is a major source of energy for Earth. Also covered: 2.1b, 2.1c, 2.1d, 2.1j, 2.2.k, 2.2l, 2.2m, 2.2n, 3.3b, 4.1d, 4.2a, 4.2b.

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  • sections

    1 Earth’s AtmosphereLab Evaluating Sunscreens

    2 Energy Transfer in theAtmosphere

    3 Air MovementLab The Heat is On

    Virtual Lab What is thestructure of Earth’satmosphere?

    Fresh mountain air?On top of Mt. Everest the air is a bit thin.Without breathing equipment, an averageperson quickly would become dizzy, thenunconscious, and eventually would die. Inthis chapter you’ll learn what makes theatmosphere at high altitudes different fromthe atmosphere we are used to.

    Write a short article describing howyou might prepare to climb Mt. Everest.Science Journal

    Atmosphere

    PS 2.1a: Nearly all the atmosphere is confined to a thin shell surrounding Earth. The atmosphere is a mixture of gases. The atmosphere is stratified into layers, each having distinct properties.Nearly all weather occurs in the lowest layer of the atmosphere. 4.1a: The Sun is a major source of energy for Earth. Also covered: 2.1b, 2.1c, 2.1d, 2.1j, 2.2.k, 2.2l, 2.2m, 2.2n, 3.3b, 4.1d, 4.2a, 4.2b.

  • Earth’s Atmospheric LayersMake the following Foldable tohelp you visualize the five layersof Earth’s atmosphere.

    Collect 3 sheets ofpaper and layerthem about 1.25 cmapart vertically. Keepthe edges level.

    Fold up the bottomedges of the paperto form 6 equal tabs.

    Fold the paper andcrease well to holdthe tabs in place.Staple along thefold. Label each tab.

    Find Main Ideas Label the tabs Earth’sAtmosphere, Troposphere, Stratosphere,Mesosphere, Thermosphere, and Exosphere frombottom to top as shown. As you read the chap-ter, write information about each layer of Earth’satmosphere under the appropriate tab.

    STEP 3

    STEP 2

    STEP 1

    1. Cut out a square of cardboard about10 cm from the side of a cereal box.

    2. Fill a glass to the brim with water.

    3. Hold the cardboard firmly over the top of the glass, covering the water, and invert the glass.

    4. Slowly remove your hand holding the cardboard in place and observe.

    5. Think Critically Write a paragraph inyour Science Journal describing what hap-pened to the cardboard when youinverted the glass and removed yourhand. How does air pressure explain whathappened?

    Observe Air PressureThe air around you is made of billions of mol-ecules. These molecules are constantly mov-ing in all directions and bouncing into everyobject in the room, including you. Air pres-sure is the result of the billions of collisions ofmolecules into these objects. Because youusually do not feel molecules in air hittingyou, do the lab below to see the effect of airpressure.

    Start-Up Activities

    ExosphereThermosphereMesosphereStratosphereTroposphere

    Earth’s Atmosphere

    161

    Preview this chapter’s contentand activities at glencoe.com

    http://www.glencoe.com

  • 162 CHAPTER 6 Atmosphere

    Importance of the AtmosphereEarth’s atmosphere, shown in Figure 1, is a thin layer of air

    that forms a protective covering around the planet. If Earth hadno atmosphere, days would be extremely hot and nights wouldbe extremely cold. Earth’s atmosphere maintains a balancebetween the amount of heat absorbed from the Sun and theamount of heat that escapes back into space. It also protects life-forms from some of the Sun’s harmful rays.

    Makeup of the AtmosphereEarth’s atmosphere is a mixture of gases, solids, and liquids

    that surrounds the planet. It extends from Earth’s surface toouter space. The atmosphere is much different today from whatit was when Earth was young.

    Earth’s early atmosphere, produced by erupting volcanoes,contained nitrogen and carbon dioxide, but little oxygen.Then, more than 2 billon years ago, Earth’s early organismsreleased oxygen into the atmosphere as they made food withthe aid of sunlight. These early organisms, however, werelimited to layers of ocean water deep enough to be shieldedfrom the Sun’s harmful rays, yet close enough to the surface

    to receive sunlight.Eventually, a layer richin ozone (O3) that pro-tects Earth from theSun’s harmful raysformed in the upperatmosphere. This pro-tective layer eventuallyallowed green plants toflourish all over Earth,releasing even moreoxygen. Today, a vari-ety of life forms,including you, dependson a certain amountof oxygen in Earth’satmosphere.

    ■ Identify the gases in Earth’satmosphere.

    ■ Describe the structure of Earth’satmosphere.

    ■ Explain what causes air pressure.

    The atmosphere makes life on Earthpossible.

    Review Vocabularypressure: force exerted on an area

    New Vocabulary

    • atmosphere• troposphere• ionosphere• ozone layer • ultraviolet radiation• chlorofluorocarbon

    Earth’s Atmosphere

    Figure 1 Earth’s atmosphere,as viewed from space, is a thinlayer of gases. The atmospherekeeps Earth’s temperature in arange that can support life.

    PS 2.1a: Nearly all the atmosphere is confined to a thin shell surrounding Earth. The atmosphere is a mixtureof gases. The atmosphere is stratified into layers, each having distinct properties. Nearly all weather occursin the lowest layer of the atmosphere. Also covered: 2.1b, 2.1c, 2.1d.

  • Gases in the Atmosphere Today’satmosphere is a mixture of the gasesshown in Figure 2. Nitrogen is the mostabundant gas, making up 78 percent of theatmosphere. Oxygen actually makes uponly 21 percent of Earth’s atmosphere. Asmuch as four percent of the atmosphere iswater vapor. Other gases that make upEarth’s atmosphere include argon and car-bon dioxide.

    The composition of the atmosphere ischanging in small but important ways. Forexample, car exhaust emits gases into theair. These pollutants mix with oxygen and other chemicals in thepresence of sunlight and form a brown haze called smog.Humans burn fuel for energy. As fuel is burned, carbon dioxideis released as a by-product into Earth’s atmosphere. Increasingenergy use may increase the amount of carbon dioxide in theatmosphere.

    Solids and Liquids in Earth’s Atmosphere In additionto gases, Earth’s atmosphere contains small, solid particles suchas dust, salt, and pollen. Dust particles get into the atmospherewhen wind picks them up off the ground and carries themalong. Salt is picked up from ocean spray. Plants give off pollenthat becomes mixed throughout part of the atmosphere.

    The atmosphere also contains small liquid droplets otherthan water droplets in clouds. The atmosphere constantly movesthese liquid droplets and solids from one region to another. Forexample, the atmosphere above you may contain liquid dropletsand solids from an erupting volcano thousands of kilometersfrom your home, as illustrated in Figure 3.

    Figure 3 Solids and liquids cantravel large distances in Earth’satmosphere, affecting regions farfrom their source.

    SECTION 1 Earth’s Atmosphere 163

    –––– ––––

    Argon(0.93%)Carbondioxide

    (0.03%)

    NeonHelium

    MethaneKrypton

    XenonHydrogen

    Ozone

    21%Oxygen

    78%Nitrogen

    Trace 1%

    Figure 2 This circle graph showsthe percentages of the gases,excluding water vapor, that makeup Earth’s atmosphere.Determine Approximately whatfraction of Earth’s atmosphere isoxygen?

    Droplets of sulfuric acid from volcanoes can producespectacular sunrises.

    On June 12, 1991, Mount Pinatubo in thePhilippines erupted, causing liquid dropletsto form in Earth’s atmosphere.

    Physical Setting

    2.1a: List the percentages ofEarth's atmospheric gases fromgreatest to least.

  • Layers of the AtmosphereWhat would happen if you left a glass of chocolate milk on

    the kitchen counter for a while? Eventually, you would see a lowerlayer with more chocolate separating from upper layers with lesschocolate. Like a glass of chocolate milk, Earth’s atmosphere haslayers. There are five layers in Earth’s atmosphere, each with itsown properties, as shown in Figure 4. The lower layers includethe troposphere and stratosphere. The upper atmospheric layersare the mesosphere, thermosphere, and exosphere. The tropo-sphere and stratosphere contain most of the air.

    Lower Layers of the Atmosphere You study, eat, sleep,and play in the troposphere which is the lowest of Earth’satmospheric layers. It contains 99 percent of the water vaporand 75 percent of the atmospheric gases. Rain, snow, and cloudsoccur in the troposphere, which extends up to about 10 km.

    The stratosphere, the layer directly above the troposphere,extends from 10 km above Earth’s surface to about 50 km. AsFigure 4 shows, a portion of the stratosphere contains higherlevels of a gas called ozone. Each molecule of ozone is made upof three oxygen atoms bonded together. Later in this section youwill learn how ozone protects Earth from the Sun’s harmful rays.

    Figure 4 Earth’s atmosphere isdivided into five layers. Describe the layer of the atmos-phere in which you live.

    500 km

    85 km

    50 km

    Earth

    10 kmJet

    Ozone layer

    Troposphere

    Stratosphere

    Mesosphere

    Thermosphere

    Exosphere

    Meteor trails

    Satellite

    Space shuttle

    164 CHAPTER 6 Atmosphere

    Topic: Earth’s AtmosphericLayers Visit for Web links toinformation about layers of Earth’satmosphere.

    Activity Locate data on recentozone layer depletion. Graph yourdata.

    glencoe.com

    http://www.glencoe.com

  • Upper Layers of the Atmosphere Beyond the strato-sphere are the mesosphere, thermosphere, and exosphere. Themesosphere extends from the top of the stratosphere to about85 km above Earth. If you’ve ever seen a shooting star, you mighthave witnessed a meteor in the mesosphere.

    The thermosphere is named for its high temperatures. Thisis the thickest atmospheric layer and is found between 85 kmand 500 km above Earth’s surface.

    Within the mesosphere and thermosphere is a layer of elec-trically charged particles called the ionosphere (i AH nuh sfihr).If you live in New Jersey and listen to the radio at night, youmight pick up a station from Boise, Idaho. The ionosphereallows radio waves to travel across the country to another city, asshown in Figure 5. During the day, energy from the Sun inter-acts with the particles in the ionosphere, causing them to absorbAM radio frequencies. At night, without solar energy, AM radiotransmissions reflect off the ionosphere, allowing radio trans-missions to be received at greater distances.

    The space shuttle in Figure 6 orbits Earth in the exosphere.In contrast to the troposphere, the layer you live in, the exo-sphere has so few molecules that the wings of the shuttle are use-less. In the exosphere, the spacecraft relies on bursts from smallrocket thrusters to move around. Beyond the exosphere is outerspace.

    How does the space shuttle maneuver in theexosphere?

    Figure 5 During the day, theionosphere absorbs radio transmis-sions. This prevents you from hear-ing distant radio stations. At night,the ionosphere reflects radiowaves. The reflected waves cantravel to distant cities.Describe what causes the iono-sphere to change between dayand night.

    Figure 6 Wings help move air-craft in lower layers of the atmos-phere. The space shuttle can’t useits wings to maneuver in the exo-sphere because so few moleculesare present.

    Boise

    New Jersey

    Day

    AM radio transmitter

    Night

    Radio waves

    Receiving antenna

    Ionosphere

    SECTION 1 Earth’s Atmosphere 165

    Physical Setting

    2a: Create a chart to comparethe layers of Earth's atmosphere.

  • 166 CHAPTER 6 Atmosphere

    Atmospheric PressureImagine you’re a football player running with

    the ball. Six players tackle you and pile one on topof the other. Who feels the weight more—you orthe player on top? Like molecules anywhere else,atmospheric gases have mass. Atmospheric gasesextend hundreds of kilometers above Earth’s sur-face. As Earth’s gravity pulls the gases toward itssurface, the weight of these gases presses down onthe air below. As a result, the molecules nearerEarth’s surface are closer together. This dense airexerts more force than the less dense air near thetop of the atmosphere. Force exerted on an area isknown as pressure.

    Like the pile of football players, air pressure isgreater near Earth’s surface and decreases higher inthe atmosphere, as shown in Figure 7. People find itdifficult to breathe in high mountains because fewer

    molecules of air exist there. Jets that fly in the stratosphere mustmaintain pressurized cabins so that people can breathe.

    Where is air pressure greater—in the exosphere or in the troposphere?

    Figure 7 Air pressuredecreases as you go higher inEarth’s atmosphere.

    How does altitude affect air pressure?

    Atmospheric gases extend hundreds of kilometers above Earth’s surface,but the molecules that make up thesegases are fewer and fewer in numberas you go higher. This means that airpressure decreases with altitude.

    Identifying the Problem The graph on the right shows

    these changes in air pressure. Notethat altitude on the graph goes uponly to 50 km. The troposphere andthe stratosphere are represented on thegraph, but other layers of the atmo-sphere are not. By examining the graph,can you understand the relationshipbetween altitude and pressure?

    Solving the Problem 1. Estimate the air pressure at an altitude

    of 5 km.2. Does air pressure change more quickly

    at higher altitudes or at lower altitudes?

    Air Pressure Changes with Altitude

    1000

    800

    600

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    0

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    re (m

    illib

    ars)

    5040302010Altitude (km)

  • SECTION 1 Earth’s Atmosphere 167

    Temperature in Atmospheric Layers The Sun is the source of most of the energy on Earth. Before

    it reaches Earth’s surface, energy from the Sun must passthrough the atmosphere. Because some layers contain gases thateasily absorb the Sun’s energy while other layers do not, the var-ious layers have different temperatures, illustrated by the redline in Figure 8.

    Molecules that make up air in the troposphere are warmedmostly by heat from Earth’s surface. The Sun warms Earth’s sur-face, which then warms the air above it. When you climb amountain, the air at the top is usually cooler than the air at thebottom. Every kilometer you climb, the air temperaturedecreases about 6.5°C.

    Molecules of ozone in the stratosphere absorb some of theSun’s energy. Energy absorbed by ozone molecules raises thetemperature. Because more ozone molecules are in the upperportion of the stratosphere, the temperature in this layer riseswith increasing altitude.

    Like the troposphere, the temperature in the mesospheredecreases with altitude. The thermosphere and exosphere arethe first layers to receive the Sun’s rays. Few molecules are inthese layers, but each molecule has a great deal of energy.Temperatures here are high.

    0

    10

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    500

    20 400 600 8000�20�40�60�80�100Temperature (�C)

    Troposphere

    Stratosphere

    Mesosphere

    ThermosphereExosphere

    Alt

    itu

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    (km

    )

    Highestconcentration

    of ozone

    Temperature of the Atmosphere at Various Altitudes

    Figure 8 The division ofthe atmosphere into layers isbased mainly on differences intemperature.Determine Does the temperatureincrease or decrease with altitude inthe mesosphere?

    Determining if AirHas MassProcedure1. On a pan balance, find the

    mass of an inflatable ballthat is completely deflated.

    2. Hypothesize about thechange in the mass of theball when it is inflated.

    3. Inflate the ball to its maxi-mum recommended infla-tion pressure.

    4. Determine the mass of thefully inflated ball.

    Analysis1. What change occurs in the

    mass of the ball when it isinflated?

    2. Infer from your datawhether air has mass.

    Physical Setting

    2.1b: Describe what happens toair pressure as altitude increases.

  • 168 CHAPTER 6 Atmosphere

    The Ozone LayerWithin the stratosphere, about 19 km to 48 km above your

    head, lies an atmospheric layer called the ozone layer. Ozone ismade of oxygen. Although you cannot see the ozone layer, yourlife depends on it.

    The oxygen you breathe has two atoms per molecule, but anozone molecule is made up of three oxygen atoms boundtogether. The ozone layer contains a high concentration ofozone and shields you from the Sun’s harmful energy. Ozoneabsorbs most of the ultraviolet radiation that enters the atmos-phere. Ultraviolet radiation is one of the many types of energythat come to Earth from the Sun. Too much exposure to ultra-violet radiation can damage your skin and cause cancer.

    CFCs Evidence exists that some air pollutants are destroying theozone layer. Blame has fallen on chlorofluorocarbons (CFCs),chemical compounds used in some refrigerators, air conditioners,and aerosol sprays, and in the production of some foam packaging.CFCs can enter the atmosphere if these appliances leak or if theyand other products containing CFCs are improperly discarded.

    Recall that an ozone molecule is made of three oxygen atomsbonded together. Chlorofluorocarbon molecules, shown in Figure 9, destroy ozone. When a chlorine atom from achlorofluorocarbon molecule comes near a molecule of ozone, theozone molecule breaks apart. One of the oxygen atoms combineswith the chlorine atom, and the rest form a regular, two-atommolecule. These compounds don’t absorb ultraviolet radiationthe way ozone can. In addition, the original chlorine atom cancontinue to break apart thousands of ozone molecules. The resultis that more ultraviolet radiation reaches Earth’s surface.

    Figure 9 Chlorofluorocarbon(CFC) molecules once were usedin refrigerators and air condition-ers. Each CFC molecule has threechlorine atoms. One atom of chlo-rine can destroy approximately100,000 ozone molecules.

    Ultraviolet lightbreaks up CFC molecule.

    A releasedchlorine atom breaksup ozone (O3) molecule.

    A free oxygenatom breaks the

    chlorine-oxygen bond.

    Oxygen atomsrejoin to form a normaloxygen (O2) molecule.

    The chlorine atom joinswith an oxygen atom,leaving behind a molecule of oxygen (O2).

    Releasedchlorine atom breaks up anotherozone (O3) molecule.

    A. B. C.

    D. E. F.

    Cl

    Cl

    Cl

    Cl ClO

    OO

    OO

    O

    O

    O

    O

    O

    Cl

    ClO

    OO

    F

    C

    UVlight

    Effects of UV Light onAlgae Algae are organ-isms that use sunlight tomake their own food.This process releasesoxygen to Earth’s atmos-phere. Some scientistssuggest that growth isreduced when algae areexposed to ultravioletradiation. Infer whatmight happen to the oxy-gen level of the atmos-phere if increasedultraviolet radiationdamages some algae.

  • Self Check1. Describe How did oxygen come to make up 21 percent

    of Earth’s present atmosphere?

    2. Infer While hiking in the mountains, you notice that itis harder to breathe as you climb higher. Explain.

    3. State some effects of a thinning ozone layer.

    4. Think Critically Explain why, during the day, the radioonly receives AM stations from a nearby city, while atnight, you’re able to hear a distant city’s stations.

    SummaryLayers of the Atmosphere

    • The atmosphere is a mixture of gases, solids,and liquids.

    • The atmosphere has five layers—troposphere, stratosphere, mesosphere,thermosphere, and exosphere.

    • The ionosphere is made up of electricallycharged particles.

    Atmospheric Pressure and Temperature

    • Atmospheric pressure decreases with distancefrom Earth.

    • Because some layers absorb the Sun’s energymore easily than others, the various layershave different temperatures.

    Ozone Layer

    • The ozone layer absorbs most UV light.• Chlorofluorocarbons (CFCs) break down the

    ozone layer.

    5. Interpret Scientific Illustrations Using Figure 2,determine the total percentage of nitrogen and oxy-gen in the atmosphere. What is the total percentageof argon and carbon dioxide?

    6. Communicate The names of the atmospheric layersend with the suffix -sphere, a word that means “ball.”Find out what tropo-, meso-, thermo-, and exo- mean.Write their meanings in your Science Journal and explain if the layers are appropriately named.

    SECTION 1 Earth’s Atmosphere 169

    The Ozone Hole The destruction ofozone molecules by CFCs seems to cause a

    seasonal reduction in ozone over Antarctica called the ozonehole. Every year beginning in late August or early September theamount of ozone in the atmosphere over Antarctica begins todecrease. By October, the ozone concentration reaches its lowestvalues and then begins to increase again. By December, theozone hole disappears. Figure 10 shows how the ozone hole overAntarctica has changed. In the mid-1990s, many governmentsbanned the production and use of CFCs. Since then, the concen-tration of CFCs in the atmosphere has started to decrease.

    Figure 10 These images ofAntarctica were produced usingdata from a NASA satellite. Thelowest values of ozone concentra-tion are shown in dark blue andpurple. These data show that thesize of the seasonal ozone holeover Antarctica has grown largerover time.

    October 1980 October 1988 October 1990 September 1999

    More Section Review glencoe.com

    http://www.glencoe.com

  • Without protection, sun exposure can damageyour health. Sunscreens protect your skin fromUV radiation. In this lab, you will draw infer-ences using different sunscreen labels.

    Real-World QuestionHow effective are various brands of sunscreens?

    Goals■ Draw inferences based on labels on sun-

    screen brands.■ Compare the effectiveness of different sun-

    screen brands for protection against the Sun.■ Compare the cost of several sunscreen brands.

    Materialsvariety of sunscreens of different brand names

    Safety Precautions

    Procedure1. Make a data table in your Science Journal

    using the following headings: Brand Name,SPF, Cost per Milliliter, and Misleading Terms.

    2. The Sun Protection Factor (SPF) tells youhow long the sunscreen will protect you. Forexample, an SPF of 4 allows you to stay inthe Sun four times longer than if you did notuse sunscreen. Record the SPF of each sun-screen on your data table.

    3. Calculate the cost per milliliter of each sun-screen brand.

    4. Government guidelines say that terms likesunblock and waterproof are misleadingbecause sunscreens can’t block the Sun’s rays,and they do wash off in water. List misleadingterms in your data table for each brand.

    Conclude and Apply1. Explain why you need to use sunscreen.

    2. Evaluate A minimum of SPF 15 is consid-ered adequate protection for a sunscreen.An SPF greater than 30 is considered bygovernment guidelines to be misleadingbecause sunscreens wash or wear off.Evaluate the SPF of each sunscreen brand.

    3. Discuss Considering the cost and effective-ness of all the sunscreen brands, discusswhich you consider to be the best buy.

    Evaluating Sunscreens

    Sunscreen Assessment

    Brand Name

    SPF

    Cost per Milliliter

    Misleading Terms

    170 CHAPTER 6 Atmosphere

    Create a poster on the proper use ofsunscreens, and provide guidelines forselecting the safest product.

    Answers will vary.

    Do not write in this book.

  • Energy from the SunThe Sun provides most of Earth’s energy. This energy drives

    winds and ocean currents and allows plants to grow and pro-duce food, providing nutrition for many animals. When Earthreceives energy from the Sun, three different things can happento that energy, as shown in Figure 11. Some energy is reflectedback into space by clouds, particles, and Earth’s surface. Some isabsorbed by the atmosphere or by land and water on Earth’ssurface.

    HeatHeat is energy that flows from an object with a higher tem-

    perature to an object with a lower temperature. Energy from theSun reaches Earth’s surface and heats it. Heat then is transferredthrough the atmosphere in three ways—radiation, conduction,and convection, as shown in Figure 12.

    Energy Transfer in the Atmosphere

    ■ Describe what happens to theenergy Earth receives from theSun.

    ■ Compare and contrast radiation,conduction, and convection.

    ■ Explain the water cycle and itseffect on weather patterns andclimate.

    The Sun provides energy to Earth’satmosphere, allowing life to exist.

    Review Vocabularyevaporation: when a liquidchanges to a gas at a temperaturebelow the liquid’s boiling point

    New Vocabulary

    • radiation • hydrosphere• conduction • condensation• convection

    Figure 11 The Sun is the sourceof energy for Earth’s atmosphere.Thirty-five percent of incomingsolar radiation is reflected backinto space.Infer how much is absorbed byEarth’s surface and atmosphere.

    6% reflected by the atmosphere

    25% reflected from clouds

    50% directly or indirectly absorbed by Earth’s surface

    15% absorbed by the atmosphere

    4% reflected from Earth’s surface

    SECTION 2 Energy Transfer in the Atmosphere 171

    PS 4.1a: The Sun is a major source of energy for Earth. 4.2b: Heat can be transferred through matter by the colli-sions of atoms and/or molecules (conduction) or through space (radiation). In a liquid or gas, currents will facili-tate the transfer of heat (convection). Also covered: 2.1j, 3.3b, 4.1d, 4.2a.

  • 172 CHAPTER 6 Atmosphere

    Radiation Sitting on the beach, you feel the Sun’s warmth onyour face. How can you feel the Sun’s heat even though youaren’t in direct contact with it? Energy from the Sun reachesEarth in the form of radiant energy, or radiation. Radiation isenergy that is transferred in the form of rays or waves. Earthradiates some of the energy it absorbs from the Sun back towardspace. Radiant energy from the Sun warms your face.

    How does the Sun warm your skin?

    Conduction If you walk barefoot on a hot beach, your feetheat up because of conduction. Conduction is the transfer ofenergy that occurs when molecules bump into one another.Molecules are always in motion, but molecules in warmerobjects move faster than molecules in cooler objects. Whenobjects are in contact, energy is transferred from warmer objectsto cooler objects.

    Radiation from the Sun heated the beach sand, but directcontact with the sand warmed your feet. In a similar way, Earth’ssurface conducts energy directly to the atmosphere. As airmoves over warm land or water, molecules in air are heated bydirect contact.

    Convection After the atmosphere is warmed by radiation orconduction, the heat is transferred by a third process called con-vection. Convection is the transfer of heat by the flow of mate-rial. Convection circulates heat throughout the atmosphere.How does this happen?

    Figure 12 Heat is transferredwithin Earth’s atmosphere byradiation, conduction, andconvection.

    Specific Heat Specificheat is the amount ofheat required to raisethe temperature of onekilogram of a substanceone degree Celsius.Substances with highspecific heat absorb alot of heat for a smallincrease in temperature.Land warms fasterthan water does. Inferwhether soil or water hasa higher specific heatvalue.

    Radiation warms the surface.

    Cooler air pushes warm air upward, creating a convection current.

    The air near Earth's surface is heated by conduction.

    Physical Setting

    4.1a, 4.2b: Describe how theSun is a major source of energyfor Earth.

  • When air is warmed, the molecules in it move apart and theair becomes less dense. Air pressure decreases because fewermolecules are in the same space. In cold air, molecules movecloser together. The air becomes more dense and air pressureincreases. Cooler, denser air sinks while warmer, less dense airrises, forming a convection current. As Figure 12 shows, radia-tion, conduction, and convection together distribute the Sun’sheat throughout Earth’s atmosphere.

    The Water CycleHydrosphere is a term that describes all the waters of Earth.

    The constant cycling of water within the atmosphere and thehydrosphere, as shown in Figure 13, plays an important role indetermining weather patterns and climate types.

    Energy from the Sun causes water to change from a liquid to agas by a process called evaporation. Water that evaporates fromlakes, streams, and oceans enters Earth’s atmosphere. If water vaporin the atmosphere cools enough, it changes back into a liquid. Thisprocess of water vapor changing to a liquid is called condensation.

    Clouds form when condensation occurs high in the atmos-phere. Clouds are made up of tiny water droplets that can col-lide to form larger drops. As the drops grow, they fall to Earth asprecipitation. This completes the water cycle within the hydros-phere. Classification of world climates is commonly based onannual and monthly averages of temperature and precipitationthat are strongly affected by the water cycle.

    SECTION 2 Energy Transfer in the Atmosphere 173

    Evaporation

    Condensation

    Precipitation

    Runoff

    Modeling HeatTransferProcedure1. Cover the outside of an

    empty soup can, withblack construction paper.

    2. Fill the can with cold waterand feel it with your fingers.

    3. Place the can in sunlightfor 1 h, then pour thewater over your fingers.

    Analysis1. Does the water in the can

    feel warmer or cooler afterplacing the can in sunlight?

    2. What types of heattransfer didyou model?

    Figure 13 In the water cycle,water moves from Earth to theatmosphere and back to Earthagain.

  • Figure 14 Earth’s atmospherecreates a delicate balance betweenenergy received and energy lost.Infer What could happen if thebalance is tipped toward receivingmore energy than it does now?

    174 CHAPTER 6 Atmosphere

    Self Check1. State how the Sun transfers energy to Earth.

    2. Contrast the atmospheres of Earth and Mars.

    3. Describe briefly the steps included in the water cycle.

    4. Explain how the water cycle is related to weatherpatterns and climate.

    5. Think Critically What would happen to temperatureson Earth if the Sun’s heat were not distributed through-out the atmosphere?

    SummaryEnergy From the Sun

    • The Sun’s radiation is either absorbed orreflected by Earth.

    • Heat is transferred by radiation (waves), con-duction (contact), or convection (flow).

    The Water Cycle

    • The water cycle affects climate.• Water moves between the hydrosphere and

    the atmosphere through a continual processof evaporation and condensation.

    Earth’s Atmosphere is Unique

    • Earth’s atmosphere controls the amount ofsolar radiation that reaches Earth’s surface.

    Earth’sAtmosphereis Unique

    On Earth, radia-tion from the Sun canbe reflected into space,absorbed by the atmo-sphere, or absorbed byland and water. Onceit is absorbed, heat canbe transferred by radi-

    ation, conduction, or convection. Earth’s atmosphere, shown inFigure 14, helps control how much of the Sun’s radiation isabsorbed or lost.

    What helps control how much of the Sun’sradiation is absorbed on Earth?

    Why doesn’t life exist on Mars or Venus? Mars is a cold, lifelessworld because its atmosphere is too thin to support life or to holdmuch of the Sun’s heat. Temperatures on the surface of Mars rangefrom 35°C to �170°C. On the other hand, gases in Venus’s denseatmosphere trap heat coming from the Sun. The temperature onthe surface of Venus is 470°C. Living things would burn instantly ifthey were placed on Venus’s surface. Life on Earth exists becausethe atmosphere holds just the right amount of the Sun’s energy.

    Heat

    Heat

    Heat

    Hea

    t

    Earth'satmosphere

    Sunlight

    Sunlight

    Sunlight

    Sunlight

    6. Solve One-Step Equations Earth is about 150 million kmfrom the Sun. The radiation coming from the Sun travelsat 300,000 km/s. How long does it take for radiation from the Sun to reach Earth?

    Physical Setting

    4.1b: Analyze the importance of the hydrosphere.

    Hot Words Hot Topics: Bk 1 pp. 90, 271

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  • Forming Wind Earth is mostly rock or land, with three-fourths of its sur-

    face covered by a relatively thin layer of water, the oceans.These two areas strongly influence global wind systems.Uneven heating of Earth’s surface by the Sun causes some areasto be warmer than others. Recall that warmer air expands,becoming lower in density than the colder air. This causes airpressure to be generally lower where air is heated. Wind is themovement of air from an area of higher pressure to an area oflower pressure.

    Heated Air Areas of Earth receive different amounts of radia-tion from the Sun because Earth is curved. Figure 15 illustrateswhy the equator receives more radiation than areas to the northor south. The heated air at the equator is less dense, so it is dis-placed by denser, colder air, creating convection currents.

    This cold, denser air comes from the poles, which receive lessradiation from the Sun, making air at the poles much cooler. Theresulting dense, high-pressure air sinks and moves along Earth’ssurface. However, dense air sinking as less-dense air rises does notexplain everything about wind.

    Air Movement

    ■ Explain why different latitudeson Earth receive differentamounts of solar energy.

    ■ Describe the Coriolis effect.■ Explain how land and water sur-

    faces affect the overlying air.

    Wind systems determine majorweather patterns on Earth.

    Review Vocabularydensity: mass per unit volume

    New Vocabulary

    • Coriolis effect • sea breeze• jet stream • land breeze

    Sun Rays

    Sun Rays

    Sun Rays

    Equator

    North Pole

    South Pole

    Figure 15 Because of Earth’s curvedsurface, the Sun’s rays strike the equatormore directly than areas toward thenorth or south poles.

    Each square meter of area at the equator receives more energy from the Sun than each square meter at the poles does.

    Near the poles, the Sun's energy strikes Earth at an angle, spreading out the energy received over a larger area than near the equator.

    PS 2.2k: The uneven heating of Earth's surface is the cause of weather. Also covered: 2.2l, 2.2m, 2.2n.

  • The Coriolis Effect What would happen if you threw a ballto someone sitting directly across from you on a moving merry-go-round? Would the ball go to your friend? By the time the ballgot to the opposite side, your friend would have moved and theball would appear to have curved.

    Like the merry-go-round, the rotation of Earth causes mov-ing air and water to appear to turn to the right north of theequator and to the left south of the equator. This is called theCoriolis (kohr ee OH lus) effect. It is illustrated in Figure 16.The flow of air caused by differences in the amount of solarradiation received on Earth’s surface and by the Coriolis effectcreates distinct wind patterns on Earth’s surface. These windsystems not only influence the weather, they also determinewhen and where ships and planes travel most efficiently.

    Global WindsHow did Christopher Columbus get from Spain to the

    Americas? The Nina, the Pinta, and the Santa Maria had nosource of power other than the wind in their sails. Early sailorsdiscovered that the wind patterns on Earth helped them navi-gate the oceans. These wind systems are shown in Figure 17.

    Sometimes sailors found little or no wind to move their sail-ing ships near the equator. It also rained nearly every afternoon.This windless, rainy zone near the equator is called the dol-drums. Look again at Figure 17. Near the equator, the Sun heatsthe air and causes it to rise, creating low pressure and little wind.The rising air then cools, causing rain.

    What are the doldrums?

    Figure 16 The Coriolis effectcauses moving air to turn to theright in the northern hemisphereand to the left in the southernhemisphere.Explain What causes this tohappen?

    Actual path of wind

    N

    S

    Path of wind without Coriolis effect

    Equator

    176 CHAPTER 6 Atmosphere

    Topic: Global Winds Visit for Web links toinformation about global winds.

    Activity Make a model of Earthshowing the locations of globalwind patterns.

    glencoe.com

    Physical Setting

    2.2k: Explain how the unevenheating of Earth's surface by theSun is the cause of weather.

    http://www.glencoe.com

  • NGS TITLE

    Figure 17

    VISUALIZINGGLOBAL WINDS

    SECTION 3 Air Movement 177

    TRADE WINDS Airwarmed near the equa-tor travels toward thepoles but gradually coolsand sinks. As the airflows back toward thelow pressure of the dol-drums, the Corioliseffect deflects the sur-face wind to the west.Early sailors, in ships like the one above, relied onthese winds to navigate global trade routes.

    C

    The Sun’s uneven heating of Earth’s surfaceforms giant loops, or cells, of moving air.The Coriolis effect deflects the surface winds

    to the west or east, setting up belts of prevailingwinds that distribute heat and moisture aroundthe globe.

    30° N

    60° N

    30° S

    60°S

    Equatorial doldrums

    Trade winds

    Westerlies

    Westerlies

    Polar easterlies

    Trade winds

    Polar easterlies

    DOLDRUMS Along theequator, heating causes air toexpand, creating a zone of lowpressure. Cloudy, rainy weather,as shown here, develops almostevery afternoon.

    B

    POLAR EASTERLIESIn the polar regions,cold, dense air sinksand moves away fromthe poles. Earth’s rota-tion deflects this windfrom east to west.

    D

    WESTERLIES Near 30° north and southlatitude, Earth’s rotation deflects air from westto east as air moves toward the polar regions.In the United States, the westerlies moveweather systems, such as this one along theOklahoma-Texas border, from west to east.

    A

    Equatorial doldrums

    Trade winds

    Westerlies

    Westerlies

    Polar easterlies

    Trade winds

    Polar easterlies

  • Surface Winds Air descending to Earth’s surface near 30°north and south latitude creates steady winds that blow in trop-ical regions. These are called trade winds because early sailorsused their dependability to establish trade routes.

    Between 30° and 60° latitude, winds called the prevailingwesterlies blow in the opposite direction from the trade winds.Prevailing westerlies are responsible for much of the movementof weather across North America.

    Polar easterlies are found near the poles. Near the northpole, easterlies blow from northeast to southwest. Near thesouth pole, polar easterlies blow from the southeast to thenorthwest.

    Winds in the Upper Troposphere Narrow belts of strongwinds, called jet streams, blow near the top of the troposphere.The polar jet stream forms at the boundary of cold, dry polar airto the north and warmer, more moist air to the south, as shownin Figure 18. The jet stream moves faster in the winter becausethe difference between cold air and warm air is greater. The jetstream helps move storms across the country.

    Jet pilots take advantage of the jet streams. When flying east-ward, planes save time and fuel. Going west, planes fly at differ-ent altitudes to avoid the jet streams.

    Local Wind Systems Global wind systems determine the major weather patterns

    for the entire planet. Smaller wind systems affect local weather.If you live near a large body of water, you’re familiar with twosuch wind systems—sea breezes and land breezes.

    Warm air

    Cold air

    Polar jet stream

    178 CHAPTER 6 Atmosphere

    Flying from Boston to Seattle may take30 min longer than flying from Seattleto Boston.Think Critically Why would it take longerto fly from east to west than it would fromwest to east?

    Figure 18 The polar jet streamaffecting North America formsalong a boundary where colderair lies to the north and warmerair lies to the south. It is a swiftlyflowing current of air that movesin a wavy west-to-east directionand is usually found between10 km and 15 km above Earth’ssurface.

    Physical Setting

    2.2l, 2.2m: Most local weathercondition changes are caused by movement of air masses.Identify two factors that determine the movement of air masses.

  • Self Check1. Conclude why some parts of Earth’s surface, such as the

    equator, receive more of the Sun’s heat than otherregions.

    2. Explain how the Coriolis effect influences winds.

    3. Analyze why little wind and much afternoon rain occurin the doldrums.

    4. Infer which wind system helped early sailors navigateEarth’s oceans.

    5. Think Critically How does the jet stream help movestorms across North America?

    SummaryForming Wind

    • Warm air is less dense than cool air.• Differences in density and pressure cause air

    movement and wind.

    • The Coriolis effect causes moving air to appearto turn right north of the equator and leftsouth of the equator.

    Wind Systems

    • Wind patterns are affected by latitude.• High-altitude belts of wind, called jet streams,

    can be found near the top of the troposphere.

    • Sea breezes blow from large bodies of watertoward land, while land breezes blow fromland toward water.

    Sea and Land Breezes Convection currents over areaswhere the land meets the sea can cause wind. A sea breeze,shown in Figure 19, is created during the day because solar radi-ation warms the land more than the water. Air over the land isheated by conduction. This heated air is less dense and has lowerpressure. Cooler, denser air over the water has higher pressureand flows toward the warmer, less dense air. A convection cur-rent results, and wind blows from the sea toward the land. Thereverse occurs at night, when land cools much more rapidlythan ocean water. Air over the land becomes cooler than air overthe ocean. Cooler, denser air above the land moves over thewater, as the warm air over the water rises. Movement of airtoward the water from the land is called a land breeze.

    How does a sea breeze form?

    Figure 19 These daily windsoccur because land heats up andcools off faster than water does.

    During the day, cool air fromthe water moves over the land,creating a sea breeze. At night,cool air over the land movestoward the warmer air over thewater, creating a land breeze.

    Warm air

    Cool air

    Sea breeze

    Warm air

    Cool air

    Sea breeze

    Warmair

    Cool air

    Land breeze

    Warmair

    Cool air

    Land breeze

    SECTION 3 Air Movement 179

    6. Compare and contrast sea breezes and land breezes.

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  • Design Your OwnDesign Your Own

    Real-World QuestionSometimes, a plunge in a pool or lake on a hot summer day feels cooland refreshing. Why does the beach sand get so hot when the waterremains cool? A few hours later, the water feels warmer than the landdoes. How do soil and water compare in their abilities to absorb andemit heat?

    Form a HypothesisForm a hypothesis about how soil and water compare in their abilitiesto absorb and release heat. Write another hypothesis about how airtemperatures above soil and above water differ during the day andnight.

    Goals■ Design an experiment

    to compare heatabsorption and releasefor soil and water.

    ■ Observe how heatrelease affects the airabove soil and abovewater.

    Possible Materialsring standsoilmetric rulerwatermasking tapeclear-plastic boxes (2)overhead light

    with reflectorthermometers (4)colored pencils (4)

    Safety Precautions

    WARNING: Be carefulwhen handling the hotoverhead light. Do not letthe light or its cord makecontact with water.

    The Heat Is On

    180 CHAPTER 6 Atmosphere

  • Test Your HypothesisMake a Plan1. As a group, agree upon and write your hypothesis.

    2. List the steps that you need to take to test your hypothesis. Includein your plan a description of how you will use your equipment tocompare heat absorption and release for water and soil.

    3. Design a data table in your Science Journal for both parts of yourexperiment—when the light is on and energy can be absorbed andwhen the light is off and energy is released to the environment.

    Follow Your Plan1. Make sure your teacher approves your plan and your data table

    before you start.

    2. Carry out the experiment as planned.

    3. During the experiment, record your observations and complete the data tablein your Science Journal.

    4. Include the temperatures of the soil and the water in your measurements.Also compare heat release for water and soil. Include the temperatures of theair immediately above both of the substances. Allow 15 min for each test.

    Analyze Your Data1. Use your colored pencils and the information in your data tables to make line

    graphs. Show the rate of temperature increase for soil and water. Graph therate of temperature decrease for soil and water after you turn the light off.

    2. Analyze your graphs. When the light was on, which heated up faster—the soilor the water?

    3. Compare how fast the air temperature over the water changed with how fastthe temperature over the land changed after the light was turned off.

    Conclude and Apply1. Were your hypotheses supported or not? Explain.

    2. Infer from your graphs which cooled faster—the water or the soil.

    3. Compare the temperatures of the air above thewater and above the soil 15 minutes after thelight was turned off. How do water and soil com-pare in their abilities to absorb and release heat?

    Make a poster showing the steps youfollowed for your experiment. Includegraphs of your data. Display your poster inthe classroom.

    LAB 181

  • This Native American prayer probably comes fromthe Tewa-speaking Pueblo village of San Juan, NewMexico. The poem is actually a chanted prayer usedin ceremonial rituals.

    Mother Earth Father Sky

    we are your childrenWith tired backs we bring you gifts you loveThen weave for us a garment of brightness

    its warp2 the white light of morning,weft3 the red light of evening,

    fringes the falling rain,its border the standing rainbow.

    Thus weave for us a garment of brightnessSo we may walk fittingly where birds sing,

    So we may walk fittingly where grass is green.

    Mother Earth Father Sky

    1 a machine or device from which cloth is produced

    2 threads that run lengthwise in a piece of cloth

    3 horizontal threads interlaced through the warp in a piece of cloth

    Song of the Sky Loom1Brian Swann, ed.

    Respond to Reading1. What metaphor does the song use to

    describe Earth’s atmosphere?2. Why do the words Mother Earth and

    Father Sky appear on either side andabove and below the rest of the words?

    3. Linking Science and Writing Write afour-line poem that uses a metaphor todescribe rain.

    In this chapter, youlearned about the

    composition of Earth’s atmosphere.The atmos-phere maintains the proper balance betweenthe amount of heat absorbed from the Sunand the amount of heat that escapes back intospace. The water cycle explains how waterevaporates from Earth’s surface back into theatmosphere. Using metaphor instead of scien-tific facts, the Tewa song conveys to the readerhow the relationship between Earth and itsatmosphere is important to all living things.

    UnderstandingLiteratureMetaphor A metaphor is a figure ofspeech that compares seemingly unlikethings.Unlike a simile, a metaphor does notuse the connecting words like or as. Whydoes the song use the image of a garmentto describe Earth’s atmosphere?

    182 CHAPTER 6 Atmosphere

  • Copy and complete the following cycle map on the water cycle.

    CHAPTER STUDY GUIDE 183

    Earth’s Atmosphere

    1. Earth’s atmosphere is made up mostlyof gases, with some suspended solids andliquids. The unique atmosphere allows lifeon Earth to exist.

    2. The atmosphere is divided into five layerswith different characteristics.

    3. The ozone layer protects Earth from toomuch ultraviolet radiation, which can beharmful.

    Energy Transfer in the Atmosphere

    1. Earth receives its energy from the Sun.Some of this energy is reflected back intospace, and some is absorbed.

    2. Heat is distributed in Earth’s atmosphere byradiation, conduction, and convection.

    3. Energy from the Sun powers the water cyclebetween the atmosphere and Earth’s surface.

    4. Unlike the atmosphere on Mars or Venus,Earth’s unique atmosphere maintains a bal-ance between energy received andenergy lost that keeps temperatures mild.This delicate balance allows life onEarth to exist.

    Air Movement

    1. Because Earth’s surface is curved, notall areas receive the same amount ofsolar radiation. This uneven heatingcauses temperature differences at Earth’ssurface.

    2. Convection currents modified by theCoriolis effect produce Earth’s global winds.

    3. The polar jet stream is a strong currentof wind found in the upper troposphere.It forms at the boundary between cold,polar air and warm, tropical air.

    4. Land breezes and sea breezes occur nearthe ocean.

    Energy from the Sun evaporates

    water.

    Cooled water vaporcondenses.

    Interactive Tutor glencoe.com

    Water vapor rises and cools.

    Clouds form.

    Water falls to Earthas precipitation.

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  • Fill in the blanks below with the correctvocabulary word or words.

    1. Chlorofluorocarbons are dangerous becausethey destroy the _________.

    2. Narrow belts of strong winds called_________ blow near the top of thetroposphere.

    3. The thin layer of air that surrounds Earth iscalled the _________.

    4. Heat energy transferred in the form ofwaves is called _________.

    5. The ozone layer helps protect us from_________.

    Choose the word or phrase that best answers thequestion.

    6. Nitrogen makes up what percentage of theatmosphere?A) 21% C) 78%B) 1% D) 90%

    7. What causes a brown haze near cities?A) conductionB) mudC) car exhaustD) wind

    8. Which is the uppermost layer of the atmosphere?A) troposphere C) exosphereB) stratosphere D) thermosphere

    9. What layer of the atmosphere has themost water?A) troposphere C) mesosphereB) stratosphere D) exosphere

    10. What protects living things from toomuch ultraviolet radiation?A) the ozone layer C) nitrogenB) oxygen D) argon

    11. Where is air pressure least?A) troposphere C) exosphereB) stratosphere D) thermosphere

    12. How is energy transferred when objectsare in contact?A) trade winds C) radiationB) convection D) conduction

    13. Which surface winds are responsible formost of the weather movement across theUnited States?A) polar easterliesB) sea breezeC) prevailing westerlies D) trade winds

    14. What type of wind is a movement of airtoward water?A) sea breezeB) polar easterliesC) land breezeD) trade winds

    15. What are narrow belts of strong windsnear the top of the troposphere called?A) doldrumsB) jet streamsC) polar easterliesD) trade winds

    184 CHAPTER REVIEW

    atmosphere p. 162chlorofluorocarbon p. 168condensation p. 173conduction p. 172convection p. 172Coriolis effect p. 176hydrosphere p. 173ionosphere p. 165

    jet stream p. 178land breeze p. 179ozone layer p. 168radiation p. 172sea breeze p. 179troposphere p. 164ultraviolet radiation p. 168

    Vocabulary Puzzlemaker glencoe.com

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  • ultraviolet radiation. In the design, use fil-tering film made for car windows. What isthe variable you are testing? What are yourconstants? Your controls?

    24. Recognize Cause and Effect Why is the insideof a car hotter than the outdoor tempera-ture on a sunny summer day?

    25. Make a Poster Find newspaper and maga-zine photos that illustrate how the watercycle affects weather patterns and climatearound the world.

    26. Experiment Design and conduct an experi-ment to find out how different surfacessuch as asphalt, soil, sand, and grassabsorb and reflect solar energy. Share theresults with your class.

    CHAPTER REVIEW 185

    Use the graph below to answer questions 27–28.

    27. Altitude and Air Pressure What is the altitudeat which air pressure is about 1,000 millibars?What is it at 200 millibars?

    28. Mt. Everest Assume the altitude on Mt. Everest isabout 10 km high. How many times greater is airpressure at sea level than on top of Mt. Everest?

    16. Explain why there are few or no clouds inthe stratosphere.

    17. Describe It is thought that life could nothave existed on land until the ozone layerformed about 2 billion years ago. Whydoes life on land require an ozone layer?

    18. Diagram Why do sea breezes occur duringthe day but not at night?

    19. Describe what happens when water vaporrises and cools.

    20. Explain why air pressure decreases with anincrease in altitude.

    21. Concept Map Copy and complete the cycleconcept map below using the followingphrases to explain how air moves to forma convection current: Cool air movestoward warm air, warm air is lifted andcools, and cool air sinks.

    22. Form Hypotheses Carbon dioxide in theatmosphere prevents some radiation fromEarth’s surface from escaping to space.Hypothesize how the temperature onEarth might change if more carbon diox-ide were released from burning fossil fuels.

    23. Identify and Manipulate Variables and ControlsDesign an experiment to find out howplants are affected by differing amounts of

    Air Pressure Changes with Altitude

    1000

    800

    600

    400

    200

    0

    Pre

    ssu

    re (m

    illib

    ars)

    5040302010Altitude (km)

    Cool air is warmedby conduction.

    Chapter Review glencoe.com

    Hot Words Hot Topics: Bk 1 (27) p. 195; (28) p. 90

    Cool air sinks

    Warm air islifted and cools.

    Cool air movestoward warm air.

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  • Intermediate-LevelScience Examination PracticeIntermediate-LevelScience Examination Practice

    Record your answers on the answer sheetprovided by your teacher or on a sheet of paper.

    Use the illustration below to answer questions 1–3.

    1 Which layer of the atmosphere contains theozone layer?(1) exosphere(2) mesosphere(3) stratosphere(4) troposphere

    2 Which atmospheric layer contains weather?(1) mesosphere(2) stratosphere(3) thermosphere(4) troposphere

    3 Which atmospheric layer contains electri-cally charged particles?(1) stratosphere(2) ionosphere(3) exosphere(4) troposphere

    4 What process changes water vapor to a liquid?(1) condensation(2) evaporation(3) infiltration(4) precipitation

    5 Which process transfers heat by contact?(1) conduction(2) convection(3) evaporation(4) radiation

    6 Which global wind affects weather in theU.S.?(1) doldrums (3) trade winds(2) easterlies (4) westerlies

    Use the illustration below to answer question 7.

    7 Which deflects winds to the west or east?(1) convection(2) Coriolis effect(3) jet stream(4) radiation

    8 Which forms during the day because waterheats slower than land?(1) easterlies (3) land breeze(2) westerlies (4) sea breeze

    9 Which is the most abundant gas in Earth’satmosphere?(1) carbon dioxide(2) nitrogen(3) oxygen(4) water vapor

    N

    S

    Equator

    Thermosphere(85-500 km)

    Exosphere (500 km )

    Mesosphere(50-85 km)

    Stratosphere(10-50 km)

    Troposphere(0-10km)

    Earth

    186 INTERMEDIATE-LEVEL SCIENCE EXAMINATION PRACTICE

  • Intermediate-LevelScience Examination PracticeIntermediate-LevelScience Examination Practice

    Record your answers on the answer sheet provided by your teacher or on a sheet of paper.

    10 Why does a land breeze form at night?

    Use the illustration below to answer questions 11–13.

    11 Identify the process illustrated

    12 Explain how this cycle affects weather patterns and climate.

    13 Analyze what happens to water that falls as precipitation and does not runoff andflow into streams.

    14 Why can flying from Seattle to Boston take less time than flying from Boston toSeattle in the same aircraft?

    15 Draw three diagrams to demonstrate radiation, convection, and conduction.

    Use the graph below to answer question 16.

    16 Analyze what happens to the air pressure as you increase in altitude. How mightthis affect athletes who compete at higher altitudes?

    Change in Air Pressure

    200

    300

    100

    0

    400

    500

    Altitude (km)

    Pre

    ssu

    re (m

    illib

    ars)

    5 10 15 20 25 30 35

    W

    XY

    Z

    187Science Examination glencoe.com

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    Glencoe Science: New York Science Grade 6Contents in BriefTable of ContentsUnit 1: Simple and Complex/Compound MachinesChapter 1: The Nature of ScienceSection 1: What is science?Section 2: Science in ActionSection 3: Models in ScienceSection 4: Evaluating Scientific ExplanationLab: What is the right answer?Lab: Identifying Parts of an Investigation

    Chapter 2: Energy and Energy ResourcesSection 1: What is energy?Section 2: Energy TransformationsLab: Hearing with Your Jaw

    Section 3: Sources of EnergyLab: Use the Internet: Energy to Power Your Life

    Chapter 3: Work and Simple MachinesSection 1: Work and PowerLab: Building the Pyramids

    Section 2: Using MachinesSection 3: Simple MachinesLab: Pulley Power

    Unit 2: The Atmosphere, Hydrosphere, and LithosphereChapter 4: States of MatterSection 1: MatterSection 2: Changes of StateLab: The Water Cycle

    Section 3: Behavior of FluidsLab: Design Your Own: Design Your Own Ship

    Chapter 5: Thermal EnergySection 1: Temperature and Thermal EnergySection 2: HeatLab: Heating Up and Cooling Down

    Section 3: Engines and RefrigeratorsLab: Design Your Own: Comparing Thermal Insulators

    Chapter 6: AtmosphereSection 1: Earth's AtmosphereLab: Evaluating Sunscreens

    Section 2: Energy Transfer in the AtmosphereSection 3: Air MovementLab: Design Your Own: The Heat is On

    Chapter 7: WeatherSection 1: What is weather?Section 2: Weather PatternsSection 3: Weather ForecastsLab: Reading a Weather MapLab: Model and Invent: Measuring Wind Speed

    Unit 3: BiodiversityChapter 8: Life's Structure and ClassificationSection 1: Living ThingsSection 2: How are living things classified?Section 3: Cell StructureLab: Comparing Cells

    Section 4: VirusesLab: Design Your Own: Comparing Light Microscopes

    Chapter 9: Interactions of LifeSection 1: Living EarthSection 2: PopulationsSection 3: Interactions Within CommunitiesLab: Feeding Habits of PlanariaLab: Design Your Own: Population Growth in Fruit Flies

    Unit 4: InterdependenceChapter 10: The Nonliving EnvironmentSection 1: Abiotic FactorsLab: Humus Farm

    Section 2: Cycles in NatureSection 3: Energy FlowLab: Where does the mass of a plant come from?

    Chapter 11: EcosystemsSection 1: How Ecosystems ChangeSection 2: BiomesLab: Studying a Land Ecosystem

    Section 3: Aquatic EcosystemsLab: Use the Internet: Exploring Wetlands

    Feature ContentsCross-Curricular ReadingsNational GeographicTIME Science in SocietyTIME Science and HistoryOops! Accidents in ScienceScience and Language ArtsScience Stats

    LABSLaunch LABMiniLABMiniLAB Try at HomeOne-Page LabsTwo-Page LabsDesign Your Own LabsModel and Invent LabsUse the Internet Labs

    ActivitiesApplying MathApplying ScienceIntegrateScience OnlineIntermediate-Level Science Examination Practice

    Student ResourcesScience Skill HandbookScientific MethodsSafety SymbolsSafety in the Science Laboratory

    Extra Try at Home LabsTechnology Skill HandbookComputer Skills

    Math Skill HandbookMath ReviewScience Applications

    Reference HandbooksUse and Care of a MicroscopeTopographic Map SymbolsWeather Map SymbolsDiversity of Life: Classification of Living OrganismsPeriodic Table of Elements

    English/Spanish GlossaryIndexCredits

    Student WorkbooksThe Nature of ScienceHands-On ActivitiesMiniLAB: Try at Home: Classifying Parts of a SystemMiniLAB: Try at Home: Forming a HypothesisMiniLab: Thinking Like a ScientistLab: What is the right answer?Lab: Identifying Parts of an InvestigationLaboratory Activity 1: Solving a Problem with a Scientific MethodLaboratory Activity 2: Modeling the WeatherFoldables: Reading and Study Skills

    Meeting Individual Needs: Extension and InterventionDirected Reading for Content MasteryDirected Reading for Content Mastery in SpanishReinforcementEnrichmentNote-taking Worksheet

    AssessmentChapter Review

    Transparency ActivitiesSection Focus Transparency ActivitiesTeaching Transparency ActivityAssessment Transparency Activity

    Energy and Energy ResourcesHands-On ActivitiesMiniLAB: Try at Home: Analyzing Energy TransformationsMiniLAB: Building a Solar CollectorLab: Hearing with Your JawLab: Use the Internet: Energy to Power Your LifeLaboratory Activity 1: Energy TransformationsLaboratory Activity 2: Hydroelectric GeneratorFoldables: Reading and Study Skills

    Meeting Individual Needs: Extension and InterventionDirected Reading for Content MasteryDirected Reading for Content Mastery in SpanishReinforcementEnrichmentNote-taking Worksheet

    AssessmentChapter Review

    Transparency ActivitiesSection Focus Transparency ActivitiesTeaching Transparency ActivityAssessment Transparency Activity

    Work and Simple MachinesHands-On ActivitiesMiniLAB: Try at Home: Work and PowerMiniLAB: Observing PulleysLab: Building the PyramidsLab: Design Your Own: Pulley PowerLaboratory Activity 1: Calculating Work and PowerLaboratory Activity 2: The BicycleFoldables: Reading and Study Skills

    Meeting Individual Needs: Extension and InterventionDirected Reading for Content MasteryDirected Reading for Content Mastery in SpanishReinforcementEnrichmentNote-taking Worksheet

    AssessmentChapter Review

    Transparency ActivitiesSection Focus Transparency ActivitiesTeaching Transparency ActivityAssessment Transparency Activity

    States of MatterHands-On ActivitiesMiniLAB: Observing VaporizationMiniLAB: Try at Home: Predicting a WaterfallLab: The Water CycleLab: Design Your Own: Design Your Own ShipLaboratory Activity 1: States of MatterLaboratory Activity 2: Crystal FormationFoldables: Reading and Study Skills

    Meeting Individual Needs: Extension and InterventionDirected Reading for Content MasteryDirected Reading for Content Mastery in SpanishReinforcementEnrichmentNote-taking Worksheet

    AssessmentChapter Review

    Transparency ActivitiesSection Focus Transparency ActivitiesTeaching Transparency ActivityAssessment Transparency Activity

    Thermal EnergyHands-On-ActivitiesMiniLAB: Try at Home: Comparing Rates of MeltingMiniLAB: Observing ConvectionLab: Heating Up and Cooling DownLab: Design Your Own: Comparing Thermal InsulatorsLaboratory Activity 1: The Effect of Temperature on Diffusion and ExpansionLaboratory Activity 2: Observing RadiationFoldables: Reading and Study Skills

    Meeting Individual Needs: Extension and InterventionDirected Reading for Content MasteryDirected Reading for Content Mastery in SpanishReinforcementEnrichmentNote-taking Worksheet

    AssessmentChapter Review

    Transparency ActivitiesSection Focus Transparency ActivitiesTeaching Transparency ActivityAssessment Transparency Activity

    AtmosphereHands-On ActivitiesMiniLAB: Determining If Air Has MassMiniLAB: Try at Home: Modeling Heat TransferLab: Evaluating SunscreensLab: Design Your Own: The Heat is OnLaboratory Activity 1: Air Volume and PressureLaboratory Activity 2: Temperature of the AirFoldables: Reading and Study Skills

    Meeting Individual Needs: Extension and InterventionDirected Reading for Content MasteryDirected Reading for Content Mastery in SpanishReinforcementEnrichmentNote-taking Worksheet

    AssessmentChapter Review

    Transparency ActivitiesSection Focus Transparency ActivitiesTeaching Transparency ActivityAssessment Transparency Activity

    WeatherHands-On ActivitiesMiniLAB: Determining Dew PointMiniLAB: Try at Home: Measuring RainLab: Reading a Weather MapLab: Model and Invent: Measuring Wind SpeedLaboratory Activity 1: Effect of Temperature on Cloud FormationLaboratory Activity 2: Wind PowerFoldables: Reading and Study Skills

    Meeting Individual Needs: Extension and InterventionDirected Reading for Content MasteryDirected Reading for Content Mastery in SpanishReinforcementEnrichmentNote-taking Worksheet

    AssessmentChapter Review

    Transparency ActivitiesSection Focus Transparency ActivitiesTeaching Transparency ActivityAssessment Transparency Activity

    Life's Structure and ClassificationHands-On ActivitiesMiniLAB: Try at Home: Communicating IdeasMiniLAB: Modeling CytoplasmLab: Comparing CellsLab: Design Your Own: Comparing Light MicroscopesLaboratory Activity 1: The MicroscopeLaboratory Activity 2: ClassificationFoldables: Reading and Study Skills

    Meeting Individual Needs: Extension and InterventionDirected Reading for Content MasteryDirected Reading for Content Mastery in SpanishReinforcementEnrichmentNote-taking Worksheet

    AssessmentChapter Review

    Transparency ActivitiesSection Focus Transparency ActivitiesTeaching Transparency ActivityAssessment Transparency Activity

    Interactions of LifeHands-On ActivitiesMiniLAB: Try at Home: Observing Seedling CompetitionMiniLAB: Comparing Biotic PotentialLab: Feeding Habits of PlanariaLab: Design Your Own: Population Growth in Fruit FliesLaboratory Activity 1: CommunitiesLaboratory Activity 2: Changes in Predator and Prey PopulationsFoldables: Reading and Study Skills

    Meeting Individual Needs: Extension and InterventionDirected Reading for Content MasteryDirected Reading for Content Mastery in SpanishReinforcementEnrichmentNote-taking Worksheet

    AssessmentChapter Review

    Transparency ActivitiesSection Focus Transparency ActivitiesTeaching Transparency ActivityAssessment Transparency Activity

    The Nonliving EnvironmentHands-On ActivitiesMiniLAB: Try at Home: Determining Soil MakeupMiniLAB: Comparing FertilizersLab: Humus FarmLab: Where does the mass of a plant come from?Laboratory Activity 1: The Rain Shadow EffectLaboratory Activity 2: Carbon Dioxide and Earth's TemperaturesFoldables: Reading and Study Skills

    Meeting Individual Needs: Extension and InterventionDirected Reading for Content MasteryDirected Reading for Content Mastery in SpanishReinforcementEnrichmentNote-taking Worksheet

    AssessmentChapter Review

    Transparency ActivitiesSection Focus Transparency ActivitiesTeaching Transparency ActivityAssessment Transparency Activity

    EcosystemsHands-On ActivitiesMiniLAB: Try at Home: Modeling Rain Forest LeavesMiniLAB: Modeling Freshwater EnvironmentsLab: Studying a Land EcosystemLab: Use the Internet: Exploring WetlandsLaboratory Activity 1: Succession Communities and GrassesLaboratory Activity 2: Exploring Life in Pond WaterFoldables: Reading and Study Skills

    Meeting Individual Needs: Extension and InterventionDirected Reading for Content MasteryDirected Reading for Content Mastery in SpanishReinforcementEnrichmentNote-taking Worksheet

    AssessmentChapter Review

    Transparency ActivitiesSection Focus Transparency ActivitiesTeaching Transparency ActivityAssessment Transparency Activity

    NY Reading Essentials Grade 6 Student EditionTo the StudentChapter 1: The Nature of ScienceChapter 2: Energy and Energy ResourcesChapter 3: Work and Simple MachinesChapter 4: States of MatterChapter 5: Thermal EnergyChapter 6: AtmosphereChapter 7: WeatherChapter 8: Life's Structure and ClassificationChapter 9: Interactions of LifeChapter 10: The Nonliving EnvironmentChapter 11: Ecosystems

    NY Science Notebook Grade 6 Student EditionNote-Taking TipsUsing Your Science NotebookChapter 1: The Nature of ScienceChapter PreviewSection 1-1Section 1-2Section 1-3Section 1-4Wrap-Up

    Chapter 2: Energy and Energy ResourcesChapter PreviewSection 2-1Section 2-2Section 2-3Wrap-Up

    Chapter 3: Work and Simple MachinesChapter PreviewSection 3-1Section 3-2Section 3-3Wrap-Up

    Chapter 4: States of MatterChapter PreviewSection 4-1Section 4-2Section 4-3Wrap-Up

    Chapter 5: Thermal EnergyChapter PreviewSection 5-1Section 5-2Section 5-3Wrap-Up

    Chapter 6: AtmosphereChapter PreviewSection 6-1Section 6-2Section 6-3Wrap-Up

    Chapter 7: WeatherChapter PreviewSection 7-1Section 7-2Section 7-3Wrap-Up

    Chapter 8: Life's Structure and ClassificationChapter PreviewSection 8-1Section 8-2Section 8-3Section 8-4Wrap-Up

    Chapter 9: Interactions of LifeChapter PreviewSection 9-1Section 9-2Section 9-3Wrap-Up

    Chapter 10: The Nonliving EnvironmentChapter PreviewSection 10-1Section 10-2Section 10-3Wrap-Up

    Chapter 11: EcosystemsChapter PreviewSection 11-1Section 11-2Section 11-3Wrap-Up

    Probeware Labs, Student EditionTo the StudentGetting Started with ProbewareSafety in the LabSafety SymbolsLife Science LabsLab 1: Size Limits of CellsLab 2: Exercise and Heart RateLab 3: Cooking with BacteriaLab 4: Sweat is CoolLab 5: Biodiversity and Ecosystems

    Earth Science LabsLab 6: The Effect of Acid Rain on LimestoneLab 7: The Formation of CavesLab 8: Measuring EarthquakesLab 9: Predicting the WeatherLab 10: How are distance and light intensity related?

    Physical Science LabsLab 11: How fast do you walk?Lab 12: Transforming EnergyLab 13: Endothermic and Exothermic ProcessesLab 14: Thermal ConductivityLab 15: Let the Races Begin!

    Appendix A: Using the TI-73 to Create a HistogramAppendix B: Using the TI-83 Plus to Create a HistogramAppendix C: Using the TI-73 to Create a Box Plot and Display StatisticsAppendix D: Using the TI-83 Plus to Create a Box Plot and Display StatisticsAppendix E: Using the TI-73 to Create a Circle Graph

    Math Skills Activities, Student EditionActivity 1Activity 2Activity 3Activity 4Activity 5Activity 6Activity 7Activity 8Activity 9Activity 10Activity 11Activity 12Activity 13Activity 14Activity 15Activity 16Activity 17Activity 18Activity 19Activity 20Activity 21Activity 22Activity 23Activity 24Activity 25Activity 26

    Reading and Writing Skill Activities, Student EditionActivity 1Activity 2Activity 3Activity 4Activity 5Activity 6Activity 7Activity 8Activity 9Activity 10Activity 11Activity 12Activity 13Activity 14Activity 15Activity 16Activity 17Activity 18Activity 19Activity 20Activity 21Activity 22Activity 23Activity 24Activity 25Activity 26

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