Unit Progress Check APES
Answer D Correct. A flow rate of 450Lmin450Lmin is the most efficient for removing particles of all sizes. For all flow rates, wet scrubbers are more efficient at removing the largest particle size.
An experiment to evaluate the efficiency of wet and dry scrubber networks that filter particulate gas at different flow rates was conducted under different flow rate conditions. The results are shown below. Based on the data in the graph, which of the following methods would be most effective at removing the greatest amount of particulate matter from coal-burning power plant emissions? A Dry scrubbers using a flow rate of 200Lmin200Lmin are best suited to remove small particles. B Dry scrubbers using a flow rate of 450Lmin450Lmin are best suited to remove large particles. C Wet scrubbers using a flow rate of 300Lmin300Lmin are best suited to remove small particles. D Wet scrubbers using a flow rate of 450Lmin450Lmin are best suited to remove large particles.
Answer D Correct. The efficiency of all flow rates for dry scrubbers is less than 10%.
An experiment to evaluate the efficiency of wet and dry scrubber networks that filter particulate gas at different flow rates was conducted under different flow rate conditions. The results are shown below. Which of the following best describes the efficiency of dry scrubbers at removing particles that are less than 2 micrometers in diameter? A Dry scrubbers are less than 20% efficient at removing particles less than 1μm1μm and increase to over 50% efficiency at removing particles between 1 and 2μm2μm. B Dry scrubbers are between 50% and 90% efficient at removing particles less than 2μm2μm, depending on the flow rate. C Dry scrubbers are between 5% and 40% efficient at removing particles less than 2μm2μm in size. D Dry scrubbers are less than 10% efficient at removing particles less than 1μm1μm in size.
Atmospheric deposition is receiving increased attention in the scientific community, and has become the subject of a specific research area in the environmental sciences. Acid rain is detrimental to our ecosystems and can be measured in several ways. Which of the following methods would best identify changes from acid deposition in an area over time? A Calculating the change in sulfur dioxide emissions from coal-burning power plants over time B Mapping out coal-burning power plant locations over the past 50 years C Measuring the pH of rainwater and surface water in affected areas D Monitoring the long-term chemical and biological parameters of an ecosystem
Atmospheric deposition is receiving increased attention in the scientific community, and has become the subject of a specific research area in the environmental sciences. Acid rain is detrimental to our ecosystems and can be measured in several ways. Which of the following methods would best identify changes from acid deposition in an area over time? A Calculating the change in sulfur dioxide emissions from coal-burning power plants over time B Mapping out coal-burning power plant locations over the past 50 years C Measuring the pH of rainwater and surface water in affected areas D Monitoring the long-term chemical and biological parameters of an ecosystem
Answer A Correct. Increasing the concentration of limestone would result in more sulfur dioxide removed from the plant emissions.
Scientists are testing the effect of different scrubber technologies on the removal of pollutants from coal power plants. The scrubbers use a slurry of limestone and water. Which of the following best describes the impact of modifying the slurry by increasing the amount of limestone? A The amount of sulfur dioxide released will decrease. B The amount of ground-level ozone released will decrease. C The amount of water released will increase. D The amount of carbon monoxide released will increase.
Answer C Correct. A location in the middle of the Pacific Ocean would provide a good average sample of air that would be less affected by areas of mass industrialization on continents.
Scientists have been collecting atmospheric CO2CO2 data for many years to monitor changes over time. Which of the following best describes why an island location, such as the Mauna Loa Observatory in Hawaii, is an ideal location to measure global CO2CO2 concentrations? A The island is also a dormant volcano, so there will be only anthropogenic atmospheric CO2CO2 measured at the site. B The location is below the inversion layer, making it less prone to local effects from industry and transportation. C The location is far from any continent, providing atmospheric air samples that are less likely to be affected by industry and transportation. D The impact of primary producers in the surrounding Pacific Ocean is negligible, reducing the effect of photosynthesis and respiration on CO2CO2 levels.
Answer C Correct. The ozone maximum is a dependent variable that is correlated to temperature.
Scientists have discovered that Volatile Organic Compounds (VOCsVOCs) emitted from trees can contribute to photochemical smog formation. Data in the table above were collected in 2006 and 2014 in Berlin, Germany. Isoprene is a VOCVOC released by some tree species. Impact factor refers to the percentage of ozone attributed to the isoprene. Which of the following best describes the relationship between variables in the data table? A Impact factor causes a change in temperature maximum. B Isoprene levels vary depending on traffic and urbanization. C Ozone maximum is correlated to average and maximum temperature. D Changes in average temperature are linked to changes in land use in Berlin.
Answer C Correct. The isoprene levels were highest in July, and the ozone level was also highest in July for both years. The impact factor shows that the increased isoprene was linked to the increased ozone.
Scientists have discovered that Volatile Organic Compounds (VOCsVOCs) emitted from trees can contribute to photochemical smog formation. Data in the table above were collected in 2006 and 2014 in Berlin, Germany. Isoprene is a VOCVOC released by some tree species. Impact factor refers to the percentage of ozone attributed to the isoprene. Which of the following claims is best supported by the data shown in the table? A Ozone levels are not a serious air quality concern in Berlin. B Ozone levels in Berlin were consistently higher in 2014 than in 2006. C Isoprene's contribution to ozone levels in Berlin was greatest in July of both years. D Isoprene levels were negatively correlated with maximum temperature.
Answer C Correct. Acid rain, as a result of pollution from the plant, would increase the acidity of the lake. If the scientists are using a control that also has acidic water, the effect of the plant would appear to be minimal because the difference in pHpH would be lower than if they used a nonacidic lake as a control.
Scientists want to examine the effects of a coal-burning power plant on the pHpH of a lake that is downwind of the power plant. They take samples from a lake that is not downwind of the power plant to serve as a control. However, they did not realize that the lake they chose as a control group was a geothermal hot spring with acidic water. Which of the following best describes how their choice of control group could affect the results of their experiment? A Using this control would not have an effect on the outcome because the high temperature of the hot spring reduces the acidity of the water in the lake. B The coal-burning power plant would appear to have a much larger effect on the pHpH of the experimental group because the pHpH in the control lake would be elevated from the acidic water. C The coal-burning power plant would not appear to have a large impact because the pHpH levels of the two lakes would be similar. D The coal-burning power plant would affect both lakes because the Coriolis effect and weather patterns would circulate pollutants in the atmosphere.
Answer A Correct. Although the amount of travel in July and December is similar, the higher UVUV radiation in July would generate more photochemical smog.
The graph shows the average distance traveled by individuals in a population in an urban area in the southwestern United States. Based on the data, which of the following months most likely experiences the highest levels of photochemical smog? A July B August C November D December
Answer B Correct. The article states that the area that predators can hear prey is reduced by 70%. This supports a potential increase in prey populations.
What is one potential impact of increased noise pollution in national parks that is supported by the article? A Predator-prey interactions will intensify in national parks because of stress caused by noise pollution. B Prey populations are likely to increase in national parks because predators have a decreased ability to hear prey sounds. C Prey populations are likely to experience biomagnification of noise pollution. D Predator species will expand their range beyond park boundaries because of increased noise pollution.
Answer B Correct. Limestone, the one independent variable in this study, can naturally buffer the acid in the rain. With the control group, this study would measure the effect of soil buffering on plant growth in a region affected by acid rain.
Which of the following best describes how a scientist could accurately study the effects of soil buffering on plant growth in a region that is affected by acid deposition downwind of a coal-burning power plant? A Measure changes in plant height over a year in a two different groups of trees; one group is 5km5km from the power plant and one group is 10km10km from the power plant. B Measure the changes in plant height over a year in two different groups of trees the same distance from the power plant; one group is in topsoil and one group is in topsoil with limestone added. C Measure changes in plant biomass over a year in two different groups of trees the same distance from the power plant; one group is not manipulated and one group is watered daily to dilute the deposition's acidity. D Measure changes in plant biomass over a year in two different groups of trees; one group is 5km5km from the power plant over limestone bedrock and one group is 10km10km from the power plant that has nitrogen and phosphorus added to the topsoil.
Answer B Correct. Warm air is less dense than cool air. Warm air is wedged higher into the atmosphere when cool air is lower in atmosphere, closer to Earth's surface. This altered temperature gradient is a thermal inversion and traps pollutants near the ground, leading to photochemical smog.
Which of the following best describes the process shown in the diagram above? A Less-dense, cool air rises up and mixes with the denser warm air above it, increasing the amount of thermal pollution in the atmosphere. B Less-dense, warm air creates a temperature inversion between more-dense layers, trapping pollutants near the ground. C Dense, warm air from the mountains on the right pushes into the less-dense, cool air mass, causing an inversion layer. D Movement of air currents over urban areas decreases the amount of photochemical smog during summer months.
Answer A Correct. CO2CO2, given off from the combustion of fossil fuels, is measured using a gas sensor or probe.
Which of the following devices is correctly paired to the air pollutant it would be used to measure? A Measuring DevicePollutant MeasuredGas sensorCO2CO2 B Measuring DevicePollutant MeasuredElectrostatic precipitatorCOCO C Measuring DevicePollutant MeasuredSound pressure level sensorParticulate Matter D Measuring DevicePollutant MeasuredCatalytic converterVOCsVOCs
Answer C Correct. In 1970 the Clean Air Act, which was passed and amended in 1977 and 1990, targeted emissions from vehicles (nitrogen oxides and hydrocarbons specifically) and required the use of catalytic converters on vehicles. Corporate Average Fuel Economy (CAFECAFE) standards were enacted in 1975 to improve the average fuel economy of cars and light trucks produced for sale in the United States, leading to the trends seen in the graph. Although the number of miles has increased, the VOCVOC emissions have decreased.
Which of the following is most responsible for the change in the emissions of volatile organic compounds ( VOCVOC ) from 1970 to 2020 as shown in the graph? A A decrease in the number of vehicles fitted with catalytic converters and an increase in the number of hybrid vehicles beginning in 1970. B A decrease in the average driving distance in the United States from 1970 to 2020 that resulted from increased urbanization. C An increase in air emission standards that began in 1970 that regulated corporate average fuel economy ( CAFECAFE ) standards. D An increase in VOCVOC emissions from car exhausts that resulted from increased driving distances from 1970 to 2020.
Answer C Correct. Radon levels tend to increase in the colder months owing to the difference in temperature inside and outside the home. If the outside temperature is drastically lower than the indoor temperature, then a vacuum is created within the home as the warm, indoor air circulates. This vacuum pulls radon into the home at a faster rate than normal, resulting in elevated radon levels.
Which of the following is the most likely reason for the trend shown in the graph of fluctuating indoor radon levels over the course of a year? A Home windows are often closed during summer months, causing the levels of radon in the house to build up. B Barometric pressure changes from summer storms can cause radon levels to increase. C Radon levels tend to increase in the colder months because of the difference in temperature inside and outside the home, which creates a vacuum pulling radon into the home at a higher rate. D Increased levels of radon are linked to burning biomass indoors, which increases in winter months when more biomass is burned for cooking and heating.
Answer D Correct. During a thermal inversion, pollutants accumulate low in the atmosphere because they cannot rise through the warm middle layer. The graph shows the temperature increases above point DD, where the warm air layer would occur during a thermal inversion. An inversion traps pollution, such as smog, close to the ground.
Which of the following points on the graph best illustrates the location where pollutants are most likely to accumulate as a result of a thermal inversion? A Point AA B Point BB C Point CC D Point D
Answer A Correct. Radon gas is released from rock during radioactive decay. It can enter a home through cracks in the foundation when the gas seeps from the rocks.
Which of the following is most likely responsible for the indoor air pollutant shown in the graph? A Cracks in the basement foundation B Synthetic fiber in carpets and furniture C Leaking water D Pet hair
Answer A Correct. Various emissions from coal-burning plants contribute to acid rain. Lakes and ponds downwind from the plant can have lower (acidic) pHpH levels as a result.
A researcher wants to determine if ponds and lakes downwind of a coal-burning power plant are affected by the plant's emissions. Which of the following would be the best parameter from the water in the ponds and lakes to measure in order to determine the effect of the plant's emissions on the aquatic ecosystems? A pHpH B Biological oxygen demand (BODBOD) C Carbon dioxide D Volatile organic compounds (VOCsVOCs)
Answer D Correct. Ground-level ozone is a secondary pollutant that forms from nitrogen oxides and volatile organic compounds, catalyzed by ultraviolet (UVUV) light. Cloud coverage would reduce the amount of UVUV light (sunlight) reaching Earth, which would result in reduced ozone formation. Levels of nitrogen dioxide would be expected to be higher as a result of decreased ground-level ozone production.
Air pollution from a power plant is being monitored for levels of nitrogen dioxide and ground-level ozone. The levels are measured daily at the same time. Which of the following best predicts the impact of a dark and cloudy day on the readings for the levels of air pollutants measured? A There will be no change in the levels of nitrogen dioxide or ground-level ozone. B There will be a decrease in the level of nitrogen dioxide and an increase in the level of ground-level ozone. C There will be an increase in the levels of both nitrogen dioxide and ground-level ozone. D There will be an increase in the level of nitrogen dioxide and a decrease in the level of ground-level ozone.
Answer D Correct. Wind direction and speed would change on different sampling days and account for both types of differences. This is the factor that should have been included in the data monitoring to account for variation.
An air pollution expert set up a monitoring program to determine the amount of particulate matter (PMPM) leaving a farmer's field after crops were harvested and the soil was bare. She set up high-volume air samplers 10 meters from each edge of the square field and collected samples weekly for two months. When she looked at her data, she was surprised by how much the PMPM levels varied, both from site to site on a given date and over time at each site. Which of the following parameters would have been best to measure to help explain the variation in her results? A Percent of cloudy days over the two months B Particle size of the soils in the field C Depth of the organic matter in the soil D Wind direction and speed
Answer D Correct. Each of these effects is discussed in the article. The author describes the effect of noise pollution on these behaviors.
Based on the author's claim in the article, which of the following statements best describes the effect of noise pollution on wildlife? A Noise pollution is being managed in such a way as to not significantly interfere with wildlife in national parks. B Noise in national parks has an overall positive effect on wildlife and has led to an increase in biodiversity. C Stressors such as winter weather, disease, and food shortages are having a greater effect on wildlife than noise pollution. D Noise pollution has a negative effect on wildlife activities such as mating, establishing territories, and predator-prey interactions.
Answer B Correct. Mineral fiber batt is the least desirable choice because it has the close to the lowest efficiency of the insulation materials and has the largest contribution to indoor air pollution.
Based on the data in the graph, which of the following insulation options is ineffective at insulating a home and greatly contributes to indoor air pollution? A Blown cellulose B Mineral fiber batt C Expanded polystyrene D Rigid foam
Answer A Correct. A dominant high pressure system keeps the warm air from rising. At night, the Sun's energy no longer heats the air near the ground, allowing the cool sea breeze (more-dense air) to wedge underneath the less-dense warm layer. This process traps the warm layer between two cooler layers, forming the inversion.
In addition to a nearby mountain range, which of the following environmental conditions would be required for the process in the diagram to occur? A A cool sea breeze and a high pressure system B A warm mountain breeze and a low pressure system C A cool sea breeze and a low pressure system D A cool mountain breeze and a high pressure system
Answer D Correct. Males are changing to a pitch of call that is not preferred by females. This would likely lead to fewer mating events and fewer successful offspring. This would lead to a decrease in the size of the frog population.
Which of the following claims is best supported by the evidence provided by the article? A Frog populations may increase in size as a result of the changes in male vocalizations. B Female frogs are beginning to prefer male frogs with higher pitched calls. C More experienced male frogs are no longer preferred by female frogs. D Frog populations may decrease in size as a result of males changing the pitch of their calls.