APES Unit 6 Review

True or False: Wood can be converted to Peat

False. Wood is not converted to peat; peat is produced by the partial decomposition of organic material.

If a country possesses large oil and gas reserves within its borders, which of the labeled rock types must be present in the underlying geology of the country?

Sedimentary. The vast majority of oil and gas reserves around the world are found in sedimentary rocks. All the source rocks for oil and gas are sedimentary.

True or False: Wood produces less carbon emissions than other forms of of energy

Wood produces more carbon emissions than natural gas, which is considered the cleanest of the fossil fuels. Wood also produces considerably more emissions than renewable sources, such as geothermal.

At which of the following locations in the nuclear power plant would an accident most likely result in the release of fission products?

containment building. The reactor vessel holds the uranium fuel that is undergoing fission reactions that result in heat production.

liquid fuel, natural gas, and coals are forms of...

fossil fuels

Natural gas, a nonrenewable fossil fuel, is often seen as an alternative fuel in the worldwide transition to a renewable energy future. Which of the following statements best explains why natural gas is often used as a fuel when countries are transitioning from nonrenewable to renewable energy sources? A Natural gas burns more efficiently and cleanly than other sources of carbon-based fossil fuels, thus contributing to a reduction in atmospheric carbon dioxide. B The infrastructure for storing and transporting natural gas can be used in the future in conjunction with hydrogen fuel technologies. C Natural gas can be used in industrial applications only, but it has great potential to replace coal as a fuel source. D The process of extracting natural gas, known as hydraulic fracturing, requires very little water or energy.

Answer A Correct. Natural gas has fewer impurities than do coal and oil, so upon combustion it emits very little sulfur dioxide or particulates and much less carbon dioxide into the atmosphere.

Which of the following identifies the air pollutants most commonly released during the burning of biomass? A Lead ( PbPb ), carbon monoxide ( COCO ), and nitric acid ( HNO3HNO3 ) B Particulate matter ( PMPM ), ozone ( O3O3 ), and carbon monoxide ( COCO ) C Carbon dioxide ( CO2CO2 ), particulate matter ( PMPM ), and carbon monoxide ( COCO ) D Polychlorinated biphenyls ( PCBsPCBs ), carbon dioxide ( CO2CO2 ), and chlorofluorocarbons ( CFCsCFCs )

Answer C Correct. All three pollutants are commonly released during the burning of biomass

Which of the following statements best describes a difference between nonrenewable and renewable energy sources? A Nonrenewable energy sources release carbon dioxide when used, whereas renewable energy sources do not release carbon dioxide. B Renewable energy sources are often obtained a long distance away from the customer, whereas nonrenewable energy sources are obtained locally. C Renewable energy sources can be replaced naturally at current consumption rates, whereas nonrenewable energy sources cannot be replaced easily. D Renewable energy sources produce energy that can be recycled after use, whereas the energy from nonrenewable energy sources cannot be recycled.

Correct. Renewable energy sources are collected from sources that can naturally be replenished on a human timescale. Nonrenewable energy sources cannot be replenished on a human timescale.

Which of the following is a disadvantage of using hydrogen fuel cells? A Hydrogen gas is not readily available on Earth. B The products of the reactions in hydrogen fuel cells damage the environment. C Hydrogen fuel cells are much less efficient in powering vehicles than internal combustion engines are. D Hydrogen fuel cells need to be very large to generate electricity.

Hydrogen fuel cells are much less efficient in powering vehicles than internal combustion engines are.

correctly depict the nuclear chain reaction that occurs in a nuclear power plant?

In this image, a neutron interacts with an atom of Uranium-235, releasing two additional neutrons. These neutrons can then interact with additional atoms of Uranium-235, causing a chain reaction.

fossil fuels are cheap source of energy?

Incorrect. Fossil fuels are heavily subsidized by the government and are not a cheap source of energy. Many renewable energy sources have long-term savings in energy generation compared to those of fossil fuels.

Main environmental concern from extracting natural gas

contaminated ground water

After the Industrial Revolution, the use of fossil fuels increased significantly. Despite the documented environmental effects of these resources and the availability of renewable resources, the use of nonrenewable sources continues.

Answer A Correct. Systems are already in place to transport and deliver fossil fuels. Additionally, coal, oil, and natural gas can be burned when energy is needed, versus wind and solar energy, the generation of which depends on environmental conditions.

Which of the following best describes an environmental problem that is often linked to the process of fracking? A Fracking operations require large tracts of land, which degrades habitat and harms wildlife. B Fracking can increase stream flow and water volume, disrupting fish migration pathways. C Wastewater from fracking operations is injected into porous rock formations, which can induce seismic activity. D Excessive nutrients, such as nitrogen and phosphorus, run off the land near fracking sites, which can lead to large algal blooms in nearby waterways.

Answer C Correct. The disposal of wastewater from fracking operations is linked to an increase in earthquakes. Fracking extracts large amounts of water from underground oil-rich rocks, then pumps the water back underground, which sometimes triggers earthquakes.

Which of the following correctly identifies the sequence of energy conversions that occur in a wind turbine? A Mechanical energy →→ kinetic energy →→ electrical energy B Potential energy →→ mechanical energy →→ kinetic energy C Kinetic energy →→ mechanical energy →→ electrical energy D Potential energy →→ electrical energy →→ mechanical energy

Answer C Correct. The kinetic energy of the wind spins the blades. The main shaft of the rotor spins (mechanical energy) a generator to generate electricity (electrical energy).

A hydrogen fuel cell-powered car driving on a highway is different from gasoline-powered cars because hydrogen fuel cell-powered cars only emit A carbon dioxide and hydrogen gas B carbon dioxide and heat C water vapor and hydrogen gas D water vapor and heat

Answer D Correct. Hydrogen fuel cells use the chemical potential energy stored in molecules of hydrogen and oxygen gas to generate electricity. This process produces water molecules and heat.

Which of the following best describes why people in less developed countries use wood as a primary energy source? A The infrastructure required to transport wood is well established. B Wood produces fewer carbon emissions than other energy sources, such as geothermal or natural gas. C Wood can be converted to peat and cheaply burned for fuel. D Wood, in the form of firewood and charcoal, is often readily available.

Answer D Correct. Wood is easy to access in less developed countries. Wood is commonly used as fuel in the forms of firewood and charcoal.

Which of the following best describes electricity generation using wind turbines? A Newer wind turbines can generate consistent electricity even when there is no wind. B Wind turbines can be constructed on either vertical or horizontal axes. C Wind turbines are rarely used offshore because they tend to float in rough seas. D Wind turbines can be used by individual homeowners but have limited effectiveness when connected to the electrical grid.

Answer B Correct. Axes of wind turbines can be either vertical or horizontal; there are benefits (and drawbacks) to each type. Turbines aligned on a horizontal axis are the primary type seen and are common in large-scale operations. Turbines with vertical axis blades are perpendicular to the ground and work well in more extreme conditions.

Which of the following is an example of the process of cogeneration? A Using timber waste products as biofuel B Using wastewater from electricity production for heating homes C Using the corn crops for ethanol fuel production D Using the reservoir behind a hydroelectric dam for recreation

Answer B Correct. Cogeneration is the use of a power plant to generate electricity and useful heat at the same time. In combined heat and power plants, wastewater is recovered and the thermal energy is used for heating.

Which of the following best explains energy transformation in hydrogen fuel cells? A Methane reacts with oxygen to produce carbon and hydrogen atoms, which releases energy. B Hydrogen reacts with oxygen to produce water, which releases energy. C In the presence of sunlight, carbon dioxide reacts with water to produce sugar and oxygen, requiring energy. D Hydrogen chloride is dissolved in water, requiring energy.

Answer B Correct. Hydrogen reacts with oxygen to produce water and energy in a hydrogen fuel cell.

Which of the following best identifies a benefit of using renewable energy sources rather than nonrenewable energy sources? A Renewable energy sources do not have negative environmental impacts, whereas nonrenewable energy sources have many negative environmental impacts. B Renewable energy sources are replenishable and are virtually inexhaustible by human consumption, whereas nonrenewable sources do not form in a short period of time. C Renewable energy sources are available uniformly throughout the world, whereas nonrenewable sources are unequally distributed. D Renewable energy technologies are more developed and more readily available than nonrenewable energy technologies.

Answer B Correct. Renewable sources, such as solar, wind, and hydroelectricity, are replenishable on a human timescale and cannot be used up by human consumption. Nonrenewable resources take long periods of time to form and are limited.

Skill 7.B 1/1 MC point Which of the following statements correctly describes a difference between biomass-fired power plants and traditional fossil-fuel-burning power plants, such as coal-fired plants? A The production of biomass does not release carbon dioxide but burning fossil fuels does. B The operational costs of biomass plants are very high when compared with traditional fossil fuel plants. C Biomass plants produce higher levels of mercury emissions than fossil fuel plants. D Biomass as a fuel source is not widely available all over the world while fossil fuels are abundant around the world.

Answer B Correct. The production of biomass plants is very expensive, and in some cases, the benefits may not be worth the costs. Transport and resource-gathering expenses are high and will likely be incurred every day. Compared to using fossil fuels, the cost of biomass energy is much higher.

Which of the following are often used for energy storage of wind power? A Converters B Generators C Batteries D Rotor blades

Answer C Correct. Batteries are a common way to store electricity generated by wind turbines. When the wind blows, batteries can be charged, and then, when the wind slows down or stops, the batteries can supplement power requirements.

Which of the following best describes how a homeowner using an off-the-grid PV solar system, as seen in the graph above, can power a home between 9:00 PM and 6:00 AM? A Switching to the electrical grid to obtain power B Relying on sources like wind or hydroelectricity in times of darkness C Using excess energy from a sunny day stored in batteries for power D Burning wood to create heat and light for the home. Answer C Correct. Batteries are the standard way to store energy for times when PVPV is not generating.

Answer C Correct. Batteries are the standard way to store energy for times when PVPV is not generating.

Which of the following is an environmental benefit associated with substituting ethanol for gasoline? A Ethanol is more energy efficient than gasoline. B Ethanol has a lower cost than gasoline. C Burning ethanol produces fewer air pollutants than burning gasoline alone. D Burning ethanol removes carbon dioxide from the atmosphere.

Answer C Correct. Ethanol is an oxygenated fuel, which has oxygen as part of its molecular structure. One environmental benefit of adding ethanol to gasoline or switching to 98 percent ethanol is that it produces lower carbon dioxide emissions and lower levels of hydrocarbons and nitrogen oxides than gasoline. Answer A Incorrect. Ethanol is an alcohol and its carbon bonds have a lower energy content than those in gasoline, making it less energy efficient. Ninety percent ethanol contains about 30 percent less energy than gasoline per gallon.

Which of the following best describes a potential negative environmental effect of fossil fuel extraction? A Fossil fuel extraction requires new infrastructure and has a high start-up cost. B Birds are injured or killed when they fly around extraction sites. C Thermal energy produced during the extraction process is released into nearby streams and lakes. D Air pollutants, such as methane and particulate matter, are emitted into the atmosphere.

Answer D Correct. The extraction of fossil fuels creates air pollutants from leaking active oil and gas wells as well as from fossil fuel transportation and processing. Toxic air pollutants, such as benzene, formaldehyde, and very small particulate matter, are all negative effects of fossil fuel extraction.