Chapter 4138

3Using Material ResourcesKey Concept A variety of natural resources are usedto make common objects.

Where do you get things you need, such as food and clothing?You may say they come from a store. But where does the store getthe things it sells? All of the objects that you need to live comefrom Earth itself.

Resources from EarthEarth’s resources can be divided into energy resources and

material resources. Energy resources are natural resources thathumans use to generate energy. Material resourcesMaterial resources are naturalresources that humans use to make objects or that are con-sumed as food and drink. These resources come from Earth’satmosphere, crust, and oceans and from the organisms thatlive on Earth.

Resources from the AtmospherePerhaps the most valuable resource in the atmosphere is the

oxygen required for plant and animal life. Oxygen is also usedto burn rocket fuel, as shown in Figure 1. Other valuable chemi-cals are found in Earth’s air. Nitrogen from the atmosphere isused as a fertilizer for agricultural plant growth. Argon is anatmospheric gas that is used inside light bulbs. Argon keepsthe glowing filament in the light bulb from burning up.

6.6.b Students know different natural energyand material resources, including air, soil, rocks,minerals, petroleum, fresh water, wildlife, andforests, and know how to classify them as renewableor nonrenewable.6.6.c Students know the natural origin of thematerials used to make common objects.

What You Will Learn• Natural resources come from the

atmosphere, from Earth’s crust,from Earth’s oceans, and fromliving things.

• Both environmental and economicfactors must be considered whendetermining the cost of usingnatural resources.

Why It MattersLearning about the natural originsof common objects will help youuse material resources wisely.

Vocabulary• material resource• petroleum

Asking Questions Read this sectionsilently. In your Science Journal, writedown questions that you have aboutthis section. Discuss your questionsin a small group.

Figure 1 Liquidoxygen from theatmosphere is usedto burn fuel in thespace shuttle.

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Section 3 Using Material Resources 139

Rock and Mineral ResourcesMinerals ranging from common sand to rare elements such

as gold and platinum are used to make objects that we use daily.Earth materials are used for construction and other industrialpurposes. Iron is used to make steel that serves as the frame-work for large buildings. Aluminum provides food and beveragepackaging but is used in larger quantities to build airplanes.Copper wiring allows electricity to be distributed efficiently.Gold is used in small quantities in computers and other elec-tronic products. Platinum serves an essential environmentalrole in catalytic converters that reduce car exhaust emissions.Salt can be harvested from sea water, as shown in Figure 2. Inaddition to its use on food, salt serves as a source of chlorinefor water treatment and for other industrial processes.

PetroleumA liquid mixture of complex hydrocarbons that is found in

Earth’s crust is called petroleum.petroleum. You may think of petroleumas a resource that is used to provide gasoline and other fuels.But petroleum is also the raw material for other products. Somecompounds in petroleum are the source of products such aswaxes, tar, and asphalt. Petroleum is also the raw material forthe manufacture of various types of polymers.

Polymers—sometimes called plastics—are made from chemi-cals that are separated out of petroleum. Polymers are usedto make materials such as clothing and pipes for plumbing.Figure 3 shows some of the many products that are made ofpolymers from petroleum.

How is petroleum used as a material resource?6.6.c

A Mineral Resource: Salt from Solar EvaporationFigure 2

material resourcematerial resource (muh TIR ee uhlREE SAWRS) a natural resource thathumans use to make objects or toconsume as food and drink

petroleumpetroleum (puh TROH lee uhm) aliquid mixture of complex hydrocar-bon compounds; used widely as afuel sourceWordwise The root petr- means“rock.” Another example is petrify.

Figure 3 This bicyclist is usinga helmet, a watch, a bicycle,gloves, and clothing that aremade partly or entirely frompetroleum.

Ocean water containsdissolved salt. Most ofthis salt is sodiumchloride. Sodium chlorideis also called halite andtable salt.

Ocean water is held in ponds. Thewater evaporates and leaves behindthe salt.

Salt is used to flavorand preserve food,to manufacture otherchemicals, and toclear ice from roads.

Chapter 4 Material Resources140

Meeting Human Needs with Natural ResourcesFigure 4

Some objects, such as sweaters, can be made from a single natural resource. A sweater can be made from wool or cotton or synthetic fiber.

Other objects, such as houses, are made from a combination of differ-ent natural resources.

Cotton comes from plants.

Synthetic fiber comes from petroleum.

Bricks are made from clay.

Wood comes from trees.

Pipes can be made from petroleum.

Wool comes from sheep.

Cement is made from limestone.

Glass is made from sand.

Quick Lab

Section 3 Using Material Resources 141

Resources from Living ThingsMany material resources that we use are provided by living

things, such as trees in the forest. Resources from living thingscan be combined with resources from Earth to make productswe need. Some of these products are shown in Figure 4.

Plant ResourcesPlants store energy as sugars and starches in seeds, nuts,

fruits, and roots. Humans harvest and eat plants to get thisstored energy. Modern agriculture produces many kinds ofplants that provide us with food and drink. Humans also growfood for domesticated animals.

Some plants, such as cotton, produce fibers that can bewoven into cloth or braided into ropes or baskets. Trees supplyfruit and nut crops, as well as wood for lumber, paper, and fuel.The sap of some trees may be used to make products rangingfrom rubber, shown in Figure 5, to maple syrup. Edible oilsare produced from many plants.

Name some common objects that are made fromplant resources. 6.6.c

Animal ResourcesIn some parts of the world, animals provide transportation

for humans and cargo. Animals help farmers till soil for plant-ing crops. Animals also provide meat, leather, and dairy andegg products. Fibers for clothing are supplied by animals suchas sheep, goats, and llamas. And animal wastes are a source ofcrop fertilizers and cooking fuel for some societies.

Figure 5 Rubbertrees are tappedto collect the sapfrom which rubber ismade. Rubber can beused to make tires,although some tiresnow contain syntheticrubber made frompetroleum.

My New MaterialCan you think of a newand useful material?Create a new substance, anddescribe its properties. Go togo.hrw.com, and type in thekeyword HY7MATW.

Products from Plants1. Mix 1 cup sawdust,

1/2 cup flour, 1 TBSPliquid starch, and 1 cupwater in a small bowl.The dough should be fairlystiff, but if it is too dry, addmore water.

2. Make an object with yourdough, and set it aside todry for 2 or 3 days. After itis dry, use sandpaper tosmooth the surface.

3. What is the natural originof the materials you usedto make your object? Arethese resources renewableor nonrenewable?

4. What other objects can youname that are made fromthe materials used here?

6.6.c

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Chapter 4 Material Resources142

The Costs of Material ResourcesThe cost of using natural resources is related to

the cost of extracting them from rock, water, or theatmosphere. Other costs include those for wastemanagement, processing, packaging, transport, andmarketing. Plant and animal resources may have addi-tional costs related to planting, feeding, fertilization,irrigation, and pest control. And the effect of resourceuse on the environment is a different kind of cost.

Economic CostsThe basic requirement for commercial products is

that the total cost of making a product must be lessthan the price that a buyer is willing to pay for it.

Steps in the manufacture of paper are shown inFigure 6. Paper is made mainly from wood pulp. High-purity clays and other ingredients are sometimesadded. At each step in the paper making process,there are costs for human labor and safety, for thematerials used, and for the energy needed. All of thesecosts will be added together to determine how muchthe manufacturer will charge for the finished paper. Ifa material resource becomes too expensive to obtain,then a cheaper resource must be used instead.

Environmental CostsThe cost of acquiring objects is sometimes more

than what is reflected in the price of the object atthe store. The price of paper at the store includesthe economic costs of making the paper. But doesthe price take into account the environmental costof the paper production? Harvesting trees for papermay destroy old-growth forests or at least disruptlocal habitats. The manufacturing process may pol-lute a nearby river or the atmosphere.

If a paper manufacturer installs pollution-controldevices in the paper factory, that cost will be addedto the monetary cost of making the paper. The priceof the paper in the store will increase to reflect theincreased cost of manufacturing. Some communi-ties pass laws that require environmental protectionprocedures. These laws might require reduced emis-sion of pollutants, reclamation of mined land, or thereplanting of harvested trees.

What are some of the environmentalcosts of using material resources? 6.6.c

Trees to WoodTrees are cut toobtain one ofthe raw materi-als needed.

Paper ProductsPaper is madeinto many kindsof products.

Wood to ChipsWood is cut intosmall chips.

Chips to PulpWood chips aremade smallerand mixed withwater and otheringredients toform pulp.

Pulp to PaperPulp is spreadout, pressed,and dried toform paper,which is col-lected on rolls.

The Production of PaperFigure 6

Recycling

Internet Resources

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Summary

Using Resources WiselyReusing and recycling, as shown in Figure 7, help reduce

the demand for some new resources. But the use of manymaterial resources will continue to increase as the world’spopulation increases. The economic cost of resources is some-times reduced by improved manufacturing efficiency andby the use of new technologies. The environmental costof using resources can also be reduced. Resources can beobtained more carefully. Land and habitats that have beendamaged by mining and by the harvesting of resources canbe restored. In some cases, lowering the environmental costsof using resources costs money. Communities must decidehow to balance these factors as they use resources.

Figure 7 These cubes are made ofused metal products that have beencompacted and are being sent to arecycling plant.

6.6.b, 6.6.c

• Resources from Earthinclude gases from theatmosphere and rocks,minerals, and petroleumfrom Earth’s crust.

• Living things provide humanswith materials, such as food,clothing, and shelter.

• Using natural resourcesinvolves both economicand environmental costs.

• Reducing the environmentalcost of using resourcessometimes involves increas-ing the economic cost.

1 Write an original definition formaterial resource andpetroleum.

2 Listing What are threeresources that can be obtainedfrom the atmosphere? How arethese resources used?

3 Describing Explain how petro-leum is used to make commonobjects .

4 Identifying Give three exam-ples of common objects that aremade from plant resources.

5 Analyzing Relationships Whydoes protecting the environmentsometimes result in an increasedprice in the store for a product?

6 Expressing Opinions Explainwhy you think it is or is notimportant to consider environ-mental costs when determiningthe price of manufacturedmaterials.

7 Applying Concepts List fivematerial resources. List whetherthey are renewable or nonre-newable. Explain your answers.

8 Making Calculations In 1990,world rice production was350 million tons. In 1999, it hadrisen to 400 million tons. Whatwas the percentage increase inworld rice production between1990 and 1999?

9 Analyzing Processes Whichenergy and material resourcesare used to make new paper?Which energy and materialresources are used to makepaper from recycled fiber? Doyou think it makes sense to recy-cle paper? Explain your answer.

Topic: Natural Resources; RecyclingSciLinks code: HY71015; HY71277