< BackNext >PreviewMain Energy Resources Preview Section 1 Natural ResourcesNatural Resources Section 2 Fossil FuelsFossil Fuels Section 3 Alternative

< Back Next > Preview Main

Energy Resources

Preview

Section 1 Natural Resources

Section 2 Fossil Fuels

Section 3 Alternative Resources

Chapter 5

Concept Mapping


Bellringer

Think about these items: a plastic sandwich bag, a pencil, a glass of water, 1 qt of motor oil, an empty aluminum can, a wooden match, salt, and some aquarium charcoal.

What do these items have in common? Write your answer in your science journal.

Chapter 5 Section 1 Natural Resources


Objectives

• Describe how humans use natural resources.

• Compare renewable resources with nonrenewable resources.

• Explain three ways that humans can conserve natural resources.



Earth’s Resources

• A natural resource is any natural material that is used by humans, such as water, petroleum, minerals, forests and animals.

• Most resources are changed and made into products that make people’s lives more comfortable and convenient.

• The energy we get from many of these resources ultimately comes from the sun’s energy.



Renewable Resources

• A renewable resource is a natural resource that can be replaced at the same rate at which it is used.

• Although many resources are renewable, they still can be used up before they can be renewed.

• Trees, for example are renewable. However, some forests are being cut down faster than new forests can grow to replace them.



Nonrenewable Resources

• Not all of Earth’s natural resources are renewable. A nonrenewable resource is a resource that forms at a rate that is much slower than the rate at which it is consumed.

• Coal, petroleum, and natural gas are examples of nonrenewable resources. When these resources are used up, humans will have to find other resources to replace them.



Conserving Natural Resources

• Whether the natural resources you use are renewable or nonrenewable, you should be careful how you use them.

• To conserve natural resources, you should try to use them only when necessary.



Conserving Natural Resources, continued

• Conserving resources also means taking care of the resources even when you are not using them.

• It is important to keep lakes, rivers, and other water resources free of pollution. Polluted water can harm plants and animals, including humans.




• Energy Conservation The energy we use to heat our homes, drive our cars, and run our computers comes from natural resources.

• Most of the natural resources that provide us energy are nonrenewable resources. If we don’t limit our use of energy now, the resources may not be available in the future.




• Conserving energy is important. You can conserve energy by being careful to use only the resources that you need.

• Turn off lights when you are not using them. Ride a bike, walk, or take a bus because these methods use fewer resources than a car.




• Reduce, Reuse, Recycle Another way to conserve natural resources is to recycle. Recycling is the process of reusing materials from waste or scrap.

• Recycling reduces the amount of natural resources that must be obtained from the Earth. Recycling paper reduces the number of trees that must be cut down to make new paper products.




• Recycling also conserves energy. Energy is required to recycle materials, but it takes less energy to recycle an aluminum can than it does to make a new one.


• Newspaper, aluminum cans, most plastic containers, and some cardboard boxes can be recycled. Check with your local recycling center to learn more.


Bellringer

What does the term fossil fuels imply about the source of these fuels? Write your answer in your science journal.

Chapter 5 Section 2 Fossil Fuels


Objectives

• Describe what energy resources are.

• Identify three different forms of fossil fuels.

• Explain how fossil fuels form.

• Describe how fossil fuels are found and obtained.

• Identify four problems with fossil fuels.



Energy Resources

• The fuels used to run cars, ships, planes, and factories, and to generate electrical energy are energy resources. Energy resources are natural resources that humans use to generate energy.

• Most of the energy we use comes from a group of natural resources called fossil fuels.



Energy Resources, continued

• A fossil fuel is a nonrenewable energy resource formed from the remains of plants and animals that lived long ago. Petroleum, coal, and natural gas are examples of fossil fuels.

• Energy is released from fossil fuels when they are burned. But because fossil fuels are a nonrenewable resource, once they are burned, they are gone.



Types of Fossil Fuels

• All living things are made up of the element carbon. Since fossil fuels are formed from the remains of plants and animals, all fossil fuels are made of carbon, too.

• Most of the carbon in fossil fuels exists as hydrogen-carbon compounds called hydrocarbons.

• Different fossil fuels have different forms. Fossil fuels may exist as liquids, gases, or solids.



Types of Fossil Fuels, continued

• Liquid Fossil Fuels: Petroleum A liquid mixture of complex hydrocarbon compounds is called petroleum. Petroleum is also commonly known as crude oil.

• Petroleum is separated into several kinds of products in refineries. Those products include gasoline, jet fuel, kerosene, diesel fuel, and fuel oil.




• More than 40% of the world’s energy comes from petroleum products. Petroleum products are the main fuel for forms of transportation, such as airplanes, trains, boats, and ships.

• Crude oil is so valuable that it is sometimes called black gold.




• Gaseous Fossil Fuels: Natural Gas A gaseous mixture of hydrocarbons is called natural gas. Most natural gas is used for heating, but it is also used for generating electrical energy.

• An advantage of natural gas is that using it causes less air pollution than using oil does. However, natural gas is very flammable. Gas leaks can lead to fires or deadly explosions.




• Methane, CH4, is the main component of natural gas. But other components, such as butane and propane, can be separated from natural gas, too.

• Butane and propane are often used as fuel for camp stoves and outdoor grills.




• Solid Fossil Fuels: Coal The solid fossil fuel that humans use most is coal. Coal is a fossil fuel that is formed underground from partially decomposed plant material.

• Coal was once the major source of energy in the United States. People burned coal in stoves to heat their homes. Man trains in the 1800s and 1900s were powered by coal-burning steam locomotives.



How Do Fossil Fuels Form?

• Petroleum and Natural Gas Formation All types of fossil fuels form from the buried remains of ancient organisms. Petroleum and natural gas form mainly from the remains of microscopic sea organisms.

• When these organisms dies, the remains settle on the ocean floor where the remains decay and are buried to become part of the ocean sediment. Over time, the sediment slowly becomes rock, trapping the decayed remains.



How Do Fossil Fuels Form?, continued

• Through physical and chemical changes over millions of years, the remains become petroleum and gas.

• Gradually, more rocks form above the rocks that contain the fossil fuels. Under the pressure of over-laying rocks and sediments, the fossil fuels can move through permeable rocks.




• Permeable rocks are rocks that allow fluids, such as petroleum and gas, to move through them.

• These permeable rocks become reservoirs that hold petroleum and natural gas, as shown on the next slide.






• Coal Formation Coal forms underground over millions of years when pressure and heat cause changes in the remains of swamp plants.

• When plants die, they sink to the bottom of the swamp. If they do not decay completely, coal formation may begin.



Coal Formation


Click below to watch the Visual Concept.

Visual Concept


Where Are Fossil Fuels Found?

• Fossil fuels are found in many parts of the world. The United States has large reserves of petroleum, natural gas, and coal.



Where Are Fossil Fuels Found?, continued

• Despite its large reserves of petroleum, the United States imports petroleum as well.

• About one-half of the petroleum used by the United States is imported form the Middle East, South America, Africa, Canada, and Mexico.



How Do We Obtain Fossil Fuels?

• The kind and location of fuel determine the method used to remove the fuel. People remove petroleum and natural gas from Earth by drilling wells into rock that contains these resources.

• Oil wells exist on land and in the ocean. For offshore drilling, engineers mount drills on platforms that are secured to the ocean floor or that float on the ocean’s surface.



How Do We Obtain Fossil Fuels?, continued

• People obtain coal either by mining deep beneath Earth’s surface or by surface mining.

• Surface mining, also known as strip mining, is the process by which soil and rock are stripped from the Earth’s surface to expose the underlying coal that is to be mined.



Problems with Fossil Fuels

• Although fossil fuels provide the energy we need, the methods of obtaining them and using them can have negative effects on the environment.

• When coal is burned without pollution controls, sulfur dioxide is released. Sulfur dioxide combines with moisture in the air to produce sulfuric acid.



Problems with Fossil Fuels, continued

• Sulfuric acid is one of the acids in acid precipitation. Acid precipitation is rain, sleet, or snow that has a high concentration of acids, often because of the pollution of the atmosphere.

• Acid precipitation negatively affects wildlife, plants, buildings, and other structures.




• Coal Mining Surface mining removes soil, which some plants need for growth and some animals need for shelter. If land is not properly restored afterward, surface mining can destroy wildlife habitats.

• Coal mining can also lower water tables and pollute water supplies. The potential for underground mines to collapse endangers the lives of miners.




• Petroleum Problems Producing, transporting, and using petroleum can cause environmental problems and endanger wildlife.

• In June 2000, an oil carrier sank off the coast of South Africa and spilled more than 400 tons of oil. The toxic oil coasted thousands of blackfooted penguins. The oil hindered the penguins from swimming and catching fish for food.




• Smog The burning of petroleum products causes an environmental problem called smog. Smog is photo-chemical haze that forms when sunlight acts upon industrial pollutants and burning fuels.

• Smog is particularly serious in cities such as Houston and Los Angeles as a result of millions of automobiles that burn gasoline.



Smog


Click below to watch the Visual Concept.

Visual Concept


Bellringer

Wind power, solar energy, and hydroelectric power are three sources of alternative energy. Which, of any, of these alternative energy sources might work well in your community? Give three reasons to support your choice.

Write your responses in your science journal.

Chapter 5 Section 3 Alternative Resources


Objectives

• Describe alternatives to the use of fossil fuels.

• List the advantages and disadvantages of using alternative energy sources.



Alternative Resources

• Most of our energy needs are met by the use of fossil fuels. But the availability of fossil fuels is limited, and once thy are used up, new supplies won’t be available for thousands -- or even millions of years.

• Obtaining and using fossil fuels has environmental consequences. To continued to have access to energy and to overcome pollution, we must find alternative sources of energy.



Splitting the Atom: Fission

• The energy released by a fission or fusion reaction is nuclear energy. Fission is a process in which the nuclei of radioactive atoms are split into two or more smaller nuclei.

• When fission takes place, a large amount of energy is released. This energy can be used to generate electrical energy.





Splitting the Atom: Fission, continued

• Pros and Cons of Fission Nuclear power plants provide alternative sources of energy that do not have the problems that fossil fuels do.

• However, nuclear power plants produce dangerous radioactive wastes, which must be removed from the plant and stored until their radioactivity decreases to a harmless level. Nuclear wastes can remain dangerously radioactive for thousands of years.



Splitting the Atom: Fission, continued

• Another problem with nuclear power plants is the potential for accidental release of radiation into the environment.

• If a plant’s cooling system were to stop working, the plant would overheat. Then, its reactor could melt and a large amount of radiation could escape.



Combining Atoms: Fusion

• Another method of getting energy from nuclei is fusion. Fusion is the joining of two or more nuclei to form a larger nucleus.

• This process releases a large amount of energy and happens naturally in the sun.





Combining Atoms: Fusion, continued

• The main advantage of fusion is that it produces few dangerous wastes.

• The main disadvantage of fusion is that very high temperatures are required for the reaction to occur. No known material can withstand such high temperatures.

• So far, controlled fusion reactions have been limited to laboratory experiments.



Chemical Energy

• Some vehicles are powered by energy generated by fuel cells. Fuel cells power automobiles by converting chemical energy into electrical energy by reacting hydrogen and oxygen into water.

• Chemical energy is the energy released when a chemical compound reacts to produce new compounds.



Chemical Energy, continued

• Once advantage of using fuel cells is that they do not create pollution -- the only byproduct is water. Fuel cells are also more efficient than internal combustion engines.

• The United States has been using fuel cells in space travel since the 1960s. One day, fuel-cell technology may be used to generate electrical energy in buildings, ships, and submarines.



Solar Energy

• The energy received by the Earth from the sun in the form of radiation is solar energy. The Earth gets more than enough solar energy to meet all of our energy needs, and this is a renewable resource.

• Solar energy can be used directly to heat buildings and generate electrical energy. However, we do not yet have the technology to generate the amount of electrical energy we need from solar energy.



Solar Energy, continued

• Sunlight can be changed into electrical energy through the use of solar cells or photovoltaic cells. Solar panels are large panels made up of many solar cells wired together.

• Solar panels mounted on the roofs of some homes and businesses provide some of the electrical energy used in the buildings.




• Solar Heating Solar energy is used for direct heating through solar collectors. Solar collectors are dark-colored boxes that have glass or plastic tops.


• A common use of solar collectors is to heat water, as shown in this figure.



• Pros and Cons of Solar Energy One of the best things about solar energy is that it doesn’t produce pollution and it is renewable.

• However, some climates don’t have enough sunny days to benefit from solar energy.

• Although solar energy is free, solar cells and solar collectors are more expensive to make than other energy systems.



Wind Power

• Energy can be harnessed from wind. Wind power is the use of a windmill to drive an electric generator.

• Wind energy is renewable, and it doesn’t cause any pollution. However, in many areas, the wind isn’t strong enough or frequent enough to create energy on a large scale.



Hydroelectric Energy

• Electrical energy that is produced by falling water is called hydroelectric energy.

• Falling water turns turbines inside hydroelectric dams and generates electrical energy for millions of people.



Hydroelectric Energy, continued

• Pros and Cons of Hydroelectric Energy After the dam is built, hydroelectric energy is inexpensive and causes little pollution.

• Hydroelectric energy is renewable because water constantly cycles from water sources to the air, to the land, and back to the water source.




• Hydroelectric energy is not available everywhere. It can be produced only where large volumes of falling water can be harnessed.

• Huge dams must be built on major rivers to capture enough water to generate significant amounts of electrical energy.




• Building large dams necessary for hydroelectric power plants often destroys other resources, such as forests and wildlife habitats.

• Large numbers of fish die each year because their migratory paths is disrupted by damns. Dams can also decrease water quality and create erosion problems.



Power from Plants

• Plants are similar to solar collectors in that both absorb energy from the sun and store it for later use.

• Leaves, wood, and other parts of plants contain the store energy. Even the dung of plant-grazing animals is high in stored energy.

• These sources of energy are called biomass. Biomass is organic matter that can be a source of energy.



Power from Plants, continued

• Burning Biomass The most common way to release biomass energy is to burn it. About half of the world’s population burn wood or charcoal to heat their homes and cook their food.

• Scientists estimate that the burning of wood and animal dung accounts for approximately 14% of the world’s total energy use.



Power from Plants, continued

• Gasohol Plants that contain sugar or starch can be made into alcohol. The alcohol can be burned as a fuel, or the alcohol can be mixed with gasoline to make a fuel called gasohol.

• Biomass is a renewable source of energy. However, producing biomass requires land that could be used for growing food.



Energy from Within Earth

• Geothermal Energy The energy produced by the heat within the Earth is called geothermal energy.

• In some areas, groundwater is heated by magma, or melted rock. Often, the heated groundwater becomes steam.

• Geysers are natural vents that discharge this steam or water in a column into the air.



Energy from Within Earth, continued• The steam and hot water can also escape through wells drilled into the rock. From these wells, geothermal power plants can harness the energy from within Earth by pumping the steam and hot water.



Energy from Within Earth, continued

• The world’s largest geothermal power plant is in California and is called The Geysers. It produces electrical energy for 1.7 million households.

• Geothermal energy can also be used to heat buildings. Buildings in Iceland are heated from the country’s many geothermal sites.



Concept Mapping

Chapter 5 Energy Resources

Use the terms below to complete the concept map on the next slide.

biomass

coal

natural gas

nonrenewable

natural resources

renewable

fossil fuels

wind energy





Documents

< BackNext >PreviewMain Energy Resources Preview Section 1 Natural ResourcesNatural Resources Section 2 Fossil FuelsFossil Fuels Section 3 Alternative