Unit 6 AP Environmental Science

The figure presents a graph of the half-life of a radioactive substance. The horizontal axis is labeled Time, in seconds, and has the numbers 0 through 20 indicated in increments of 5 from left to right. The horizontal axis is labeled amount, in moles, and has the numbers 0.00 through 0.20 indicated in increments of 0.05 from bottom to top. A smooth curve connects the data points on the line. The data are as follows: 0 seconds, 0.20 moles. 2.5 seconds, 0.155 moles. 5 seconds, 0.12 moles. 7.5 seconds, 0.095 moles. 10 seconds, 0.075 moles. 12.5 seconds, 0.06 moles. 15 seconds, 0.045 moles. 17.5 seconds, 0.035 moles. 20 seconds, 0.029 moles. The half-life of a radioactive substance with the decay rate shown in the graph above is closest to

7 seconds

Extraction of natural gas by the process of hydraulic fracturing (fracking) is most likely to result in which of the following environmental problems? Responses A Groundwater contamination B Ozone depletion C Eutrophication D Denitrification E Desertification

A Groundwater contamination

Which of the following is a way for the government to encourage efficient energy use? Responses A Requiring higher fuel economy standards for new cars B Implementing government subsidies to keep gasoline prices low C Raising the speed limit from 55 to 70 miles per hour D Limiting the development of public transportation systems E Removing all taxes from gasoline at the fuel pump

A) Requiring higher fuel economy standards for new cars

An industry uses natural gas for manufacturing and uses the waste heat to produce electricity. This is an example of which of the following processes? Responses A Cogeneration B Electrolysis C Gas hydration D Gasification E Reclamation

A) cogeneration

This is the location of the world's largest hydroelectric dam, with a generating capacity of 22,500MW. Responses A B C D

Answer C Correct. In 2012, the Three Gorges Dam in China became the largest hydroelectric dam in the world, replacing the Itaipú Hydroelectric Dam in Brazil and Paraguay.

Which of the following negative consequences is most often associated with using biomass for energy production? Responses A Using biomass for energy production requires long-term storage for radioactive waste. B Using biomass for energy production can increase salinization in agricultural fields. C Using biomass for energy production releases carbon sequestered in fossil fuels into the atmosphere. D Using biomass for energy production can result in local deforestation.

Answer D Correct. Trees can be overharvested in areas using biomass for energy production, resulting in deforestation in those areas

A major limitation of using photovoltaic cells to generate electricity is that they... A)do not produce as much CO2 as other energy sources do B) do not produce as much electricity on cloudy days C) have no moving parts D) present a danger to birds and bats E) cannot be connected to the electrical grid

B)do not produce as much electricity on cloudy days

Which of the following describes an environment where large amounts of oil could form millions of years in the future? Responses A A volcanic island located along the mid-ocean ridge B A large glacier in a mountainous area C A river delta in a forested region D An area of sand dunes in a desert

C A river delta in a forested region

Which of the following accurately describes a fuel cell vehicle? Responses A Fuel cell vehicles run on both an internal combustion engine and a backup battery. B Fuel cell vehicles are able to convert waste oil from the food industry into ethanol, which is burned as a source of power. C Fuel cell vehicles use hydrogen to generate electricity that runs the motor. D Fuel cell vehicles generate energy by creating a flow of electrons in a semiconducting material such as silicon. E Fuel cell vehicles use methane to heat water, which creates steam that turns a turbine to generate electricity.

C Fuel cell vehicles use hydrogen to generate electricity that runs the motor.

Which of the following is an unintended consequence of the use of hydroelectric dams for electricity generation? A)Greenhouse gases will be released from the hydroelectric dam during the generation of electricity. B)The frequency of floods will increase downstream from the hydroelectric dam. C)There will be more erosion than sediment deposition downstream from the hydroelectric dam. D)The population of fish that migrate to areas upstream from the hydroelectric dam to breed will increase.

C Correct. Sediments that can be transported to the coastline downstream in a free-flowing river settle out in the reservoir behind the dam. As a result, erosion will most likely outpace deposition along the coastline, leading to increased beach erosion.

Which of the following actions would reduce global greenhouse emissions? A)increasing use of automobiles B) decreasing number of nuclear power plants C) replacing coal burning power plants with wind farms D) converting tropical forests to rice paddies E) switching from hydroelectric power generation to power generation using natural gas as the primary fuel

C-correct-replacing coal burning power plants with wind farms

The Chernobyl nuclear disaster led to the release of massive radiation, specifically iodine-131 and cesium-137, which has been connected to a variety of environmental problems in the 30 years following the disaster. A Cooling tower B Turbine C Generator D Reactor core

D Reactor core

One solution for reducing the amount of atmospheric carbon dioxide would be to Responses A increase oceanic temperatures to enhance carbon dioxide uptake B increase the rate of removal of tropical rain forests C decrease the total area of rice paddies D decrease the use of fossil fuels E decrease the production of chlorofluorocarbons

D decrease the use of fossil fuels

Between 1960 and 1970, world oil consumption approximately doubled. Which of the following explanations is consistent with this increase? Responses A The number of passengers per car increased. B People drove less, conserving gasoline. C The price of gasoline increased. D The number of cars on the road increased. E Cars that were more fuel-efficient were manufactured.

D) # of cars on road increased

An automobile travels at an avg speed of 55 mph w a max speed of 65 mph. It travels a distance of 75 mph and consumes a total of 2.8 gallons of fuel. Which of the following represents the correct calculation for the fuel efficiency of the automobiles? A) 65 mph/55 mph B) 75 mph/55 mph C) 65 mph/2.8 gal D)75 mph/2.8 mph

D-correct-This calculation is the measure of distance traveled per unit of fuel (such as miles per gallon), which is the fuel efficiency

Which of the following is considered an advantage of using nuclear power to generate electricity? Responses A No waste is generated. B There is a limitless supply of the raw material needed for the process of generating energy. C Nuclear power plants are inexpensive to build and maintain. D There is no potential for thermal pollution. E There is no CO2 emitted from the nuclear reaction.

E There is no CO2 emitted from the nuclear reaction.

In contrast to low-level radioactive waste, most high-level radioactive waste is currently Responses A put into steel drums and dumped into the ocean B incinerated C buried in government landfills D recycled E stored at reactor sites

E stored at reactor sites

A)Biomass B)Wind C)Tidal energy D)Nuclear fission E) Sunlight The source that is converted directly into electrical energy by photovoltaic cells

E) Sunlight

The following questions refer to the energy sources listed. (A) Uranium-238 (B) Coal (C) Natural gas (D) Oil (E) Solar Is renewable Responses

E) solar

Some automobiles in the United States are fueled by natural gas. What is the primary environmental advantage of natural gas relative to gasoline as a transportation fuel? Responses A The United States has 60% of the world's proven natural gas reserves. B Natural gas is a renewable resource that is usually produced from corn and other agricultural products. C When natural gas is burned in an automobile engine, the only emission product is water vapor. D Natural gas combustion emits fewer pollutants. E There is an extensive retail distribution network for natural gas so that natural gas is available at most gas stations.

Natural gas combustion emits fewer pollutants.

This type of energy utilizes heat that is stored beneath Earth's surface to heat water and produce steam. Responses A Solar Energy B Wind Energy C Geothermal Energy D Nuclear Energy

answer C Correct. Geothermal energy relies on heat from Earth's interior to heat water that becomes steam. This steam is then used to power electric generators.

Which of the following pieces of evidence does the author use to support the claim that the solar panel installation on the StuyTown complex is the largest in Manhattan? Responses A)The StuyTown project increased the solar capacity of the city to 3.9 megawatts. B) The installation added 9,000 solar panels to 56 rooftops, effectively doubling the total solar capacity of the surrounding area. C)New York City now has around 200 megawatts more in total solar capacity than Los Angeles does. D)After completion of the StuyTown project, the state attributed 70% of its power generation to solar energy.

Answer B Correct. The author states that the 9,000 new solar panels added about 3.9 megawatts to the solar capacity of the borough, enough to power 1,100 apartments.

Which of the following is a disadvantage of using nuclear energy as a source of electricity? Responses A Energy production is not consistent from day to day. B Cooling towers release contaminants into the atmosphere. C Spent fuel rods must be disposed of properly. D Volatile organic compounds are released into groundwater.

Answer C Correct. Nuclear power plants use radioactive materials such as uranium to produce steam that turns turbines. The half-life of the nuclear waste that is generated can be very long, and therefore trying to find a safe storage place for radioactive material is challenging.

Which of the following is a negative consequence associated with photovoltaic solar cells? Responses A Photovoltaic solar cells increase the reliance on transport of fuels long distances from energy sources to homeowners. B Smog and ground-level ozone can be created from pollutants released from photovoltaic solar cells during electricity generation. C The manufacture of photovoltaic solar cells involves toxic metals that can be released into the environment. D The installation of photovoltaic solar cells on houses and other buildings can result in the release of chemicals that destroy stratospheric ozone.

Answer C Correct. The manufacture of photovoltaic solar cells can release cadmium telluride, copper indium selenide, lead, polyvinyl fluoride, and other toxic metals into the environment.

Which of the following best describes how electricity is generated using photovoltaic cells? Responses A The Sun's rays warm water that boils and spins a turbine. B The Sun's rays warm air that turns propeller blades attached to a rotor. C Photons of light excite electrons that result in a flow of current. D Photons of light activate a generator that converts chemical energy into mechanical energy.

Answer C Correct. The semiconductor releases electrons that flow as current when sunlight strikes the surface of a photovoltaic cell.

This type of energy is considered a nonrenewable energy source. Responses A Solar Energy B Wind Energy C Geothermal Energy D Nuclear Energy

Answer D Correct. Nuclear energy is considered a nonrenewable source of energy since it relies on the fission of radioactive uranium-235, which is a limited resource.