---
title: "AP Environmental Science Unit 7 Practice Test"
description: "A timed AP Environmental Science Unit 7 (Atmospheric Pollution) practice test in the AP format, drawn from 2,403 multiple-choice questions and 50 FRQs written for the unit. The standard version takes about 70 minutes."
canonical: "https://fiveable.me/ap-enviro/unit-test/7"
type: "unit-test"
subject: "AP Environmental Science"
unit: "Unit 7"
---

# AP Environmental Science Unit 7 Practice Test

## Overview

A timed AP Environmental Science Unit 7 (Atmospheric Pollution) practice test in the AP format, drawn from 2,403 multiple-choice questions and 50 FRQs written for the unit. The standard version takes about 70 minutes.

## Test Format

- 20 Multiple Choice Questions (23 minutes)
- 1 FRQ – FRQ 1 – Design an Investigation (23 minutes)
- 1 FRQ – FRQ 2 – Analyze and Interpret Quantitative Data (23 minutes)

## Unit FRQs by Type

- [FRQ 1 – Design an Investigation](/ap-enviro/frqs/design-an-investigation?unit=7): 13 questions
- [FRQ 2 – Analyze and Interpret Quantitative Data](/ap-enviro/frqs/data-analysis?unit=7): 18 questions
- [FRQ 3 – Analyze an Environmental Problem Doing Calculations](/ap-enviro/frqs/calculations?unit=7): 19 questions

## Practice Questions

### Question 1

Atmospheric nitrogen deposition in a temperate forest averages 15 kg/hectare/year from fossil fuel combustion and industrial emissions. Soil nitrogen content has increased 40% over 30 years, while forest productivity has not increased proportionally. Understory plant diversity has declined by 50%, with nitrogen-demanding species replacing shade-tolerant species. Soil pH has decreased by 0.8 units. Which of the following best describes the environmental problem in this forest?

- (A) Excess atmospheric nitrogen deposition exceeds plant demand and soil denitrification capacity, causing nitrogen accumulation that disrupts the nitrogen cycle, acidifies soil, and alters plant community composition
- (B) Atmospheric nitrogen deposition provides beneficial nutrient input that increases soil nitrogen, but forest productivity fails to increase because other nutrients are limiting, not because of nitrogen cycle disruption
- (C) Nitrogen deposition is being rapidly denitrified by soil bacteria, converting it back to atmospheric nitrogen and preventing nitrogen accumulation in soil, but this denitrification process produces nitrous oxide that acidifies soil
- (D) Atmospheric nitrogen deposition is being assimilated by understory plants, which are converting it into biomass, but the nitrogen-demanding species are outcompeting shade-tolerant species, reducing overall forest productivity

**Answer: (A)** Describing this environmental problem requires understanding that anthropogenic nitrogen input through atmospheric deposition creates nitrogen cycle disruption. The correct answer identifies that excess nitrogen accumulation (evidenced by soil nitrogen increase not matched by productivity increase) indicates that denitrification and assimilation cannot process the input. The pH decrease reflects nitrogen cycle disruption (nitrification produces acid), and the plant community shift reflects nitrogen saturation effects. This demonstrates understanding of how nitrogen reservoir interactions affect multiple ecosystem properties.

### Question 2

Over 30 years lichens fell from 12 to 3 species near a coal plant but rose from 8 to 18 species 15 km away. SO2 was 85 ppb near the plant and 8 ppb at the distant site. What do these data suggest about lichens as indicators of air quality?

- (A) Lichen diversity declines with high sulfur dioxide, so lichens indicate air quality.
- (B) Lichen diversity increases near the plant implying pollution promotes lichen growth.
- (C) Lichen diversity differences arise from competition with mosses, not air quality.
- (D) Moss competition near the plant rather than pollution explains lichen declines.

**Answer: (A)** Lichens are sensitive to atmospheric sulfur dioxide so higher SO2 reduces species diversity. The data show diversity fell from 12 to 3 at 85 ppb while rising from 8 to 18 at 8 ppb, demonstrating an inverse relationship.

### Question 3

A recent volcanic eruption ejected ash and aerosol particles into the stratosphere. Afterward, the amount of solar radiation reaching Earth's surface dropped noticeably, and short-term cooling followed. Which geographic/geologic characteristic of the volcanic eruption best explains the short-term climate cooling?

- (A) Stratospheric ash and aerosol particles reflect and scatter incoming solar radiation, reducing the energy reaching Earth's surface and causing temporary cooling
- (B) Stratospheric ash and aerosol particles absorb incoming solar radiation, reducing the energy reaching Earth's surface and causing temporary cooling
- (C) Tropospheric ash and aerosol particles reflect and scatter incoming solar radiation, reducing the energy reaching Earth's surface and causing temporary cooling
- (D) Stratospheric ash and aerosol particles reflect and scatter incoming solar radiation, reducing the energy reaching the stratosphere and causing temporary atmospheric cooling

**Answer: (A)** Interpreting the radiation diagram requires recognizing that volcanic aerosols create a geographic/geologic climate effect by altering the atmosphere's radiative properties. The diagram's visual reduction in solar radiation reaching the surface directly results from particles scattering and reflecting sunlight back to space. This demonstrates EK ENG-2.B.1 (geologic factors affecting climate). Students must connect the visual radiation reduction to the mechanism of aerosol scattering, understanding that volcanic emissions temporarily modify Earth's energy balance.

### Question 4

A study of dust and particulate matter from coal mining operations measured air quality at a single monitoring station 500 meters downwind from the mine using daily 24-hour average measurements. If researchers modified the procedure to include monitoring stations at multiple distances (250m, 500m, 1000m, 2000m) downwind, with measurements taken every 4 hours instead of daily averages, how would these modifications most likely affect their understanding of mining's air quality impacts?

- (A) Spatial variation in dust concentration and temporal patterns related to mining operations and weather conditions could be identified.
- (B) Air quality would improve at greater distances because dust particles settle out, making the modification scientifically unnecessary.
- (C) More frequent measurements would improve accuracy, but sampling at multiple distances would create inconsistent data due to different local wind patterns.
- (D) The modification would be impractical because daily averages are already sufficient to determine if mining operations comply with air quality standards.

**Answer: (A)** Multiple downwind locations reveal how dust disperses with distance from the source, while 4-hour measurements capture diurnal patterns and episodic emission events that daily averages would miss. These modifications directly address the ecological impact of coal mining by characterizing both the extent of air contamination and its temporal variability, which affects human and ecosystem exposure.

### Question 5

Researchers report each subsurface coal mine emits 15,000 cubic meters of methane annually and methane is 28 times more potent than CO2 over 100 years. They conclude coal mining significantly contributes to regional greenhouse gas emissions. Which evidence would most strengthen this conclusion?

- (A) Regional totals showing coal mine methane makes a substantial share
- (B) Mechanism explaining why subsurface coal mining releases methane
- (C) Historical trend data showing mine methane rose over 20 years
- (D) Evidence that some mines capture methane for energy use

**Answer: (A)** Regional totals reveal mining methane's share of overall emissions and quantify its impact. Comparing per-mine volumes and global warming potential to regional totals shows whether mining is a significant regional contributor.

### Question 6

Environmental health researchers measured particulate matter (PM2.5 and PM10) concentrations using air quality monitors at 4 locations within 2 km of an active surface mine and 4 reference locations 10 km away. Daily measurements were recorded for 24 months. Which research design choice most directly enables scientists to assess the dust impact from surface mining on nearby communities?

- (A) The spatial gradient design (near mine vs. reference locations) combined with daily measurements over 24 months isolates mining-specific dust from background particulate matter and captures seasonal dust patterns
- (B) The spatial gradient design (near mine vs. reference locations) combined with weekly measurements over 24 months isolates mining-specific dust from background particulate matter and captures seasonal dust patterns
- (C) The spatial gradient design (near mine vs. reference locations) combined with daily measurements over 24 months compares absolute PM concentrations between locations and captures seasonal dust patterns
- (D) The spatial gradient design (near mine vs. reference locations) combined with daily measurements over 24 months isolates mining-specific dust from background particulate matter and determines whether concentrations exceed regulatory thresholds

**Answer: (A)** Reference locations 10 km away measure background particulate matter unaffected by mining operations, while near-mine locations capture mining dust plus background levels. The difference between these locations quantifies mining-specific dust impact. Daily measurements over two years reveal seasonal patterns in both mining dust generation and atmospheric conditions, preventing seasonal bias. Measuring both PM2.5 and PM10 captures the full range of dust particle sizes relevant to human health.

### Question 7

During geothermal power plant operation, hydrogen sulfide gas is released when hot geothermal fluids reach the surface and pressure decreases. This H₂S can react with oxygen in the atmosphere to form sulfur dioxide. Which of the following best describes the environmental consequence of this atmospheric reaction?

- (A) Sulfur dioxide dissolves in atmospheric moisture to form sulfuric acid, which falls as acid precipitation that can damage ecosystems and infrastructure
- (B) Sulfur dioxide combines with nitrogen oxides to form ground-level ozone, which reduces visibility and harms respiratory health
- (C) Sulfur dioxide is rapidly converted to elemental sulfur, which precipitates as yellow dust and accumulates in soil without further environmental impact
- (D) Sulfur dioxide increases atmospheric albedo by forming reflective sulfate particles, which reduces solar radiation reaching Earth's surface and cools the climate

**Answer: (A)** Understanding this consequence requires recognizing the multi-step process: H₂S oxidation to SO₂, then SO₂ dissolution in atmospheric water to form sulfuric acid (H₂SO₄), resulting in acid precipitation. This demonstrates comprehension of how geothermal emissions contribute to acid deposition, a key environmental effect mentioned in the EK. Students must describe the chemical transformation and its ecosystem impact.

### Question 8

A geothermal plant in a tectonically active area supplies 500,000 residents at full capacity. H2S emissions exceed standards by 40% and cause respiratory complaints. The plant cannot cut generation. Which solution best meets air quality standards while maintaining required output?

- (A) Install H2S capture and conversion system to produce elemental sulfur
- (B) Raise stack height to dilute H2S plumes without removing the pollutant
- (C) Scrub and temporarily store H2S in pressure tanks pending disposal
- (D) Use catalytic oxidation not optimized for high H2S concentrations

**Answer: (A)** Capture and convert H2S into elemental sulfur or sulfuric acid to remove the pollutant while allowing full generation. Processes such as the Claus reaction or biodesulfurization produce stable, marketable sulfur products.

### Question 9

A geothermal power plant in the Philippines operates by extracting steam from underground reservoirs and using it to drive turbines. During operation, the plant releases hydrogen sulfide gas into the atmosphere. Which of the following represents an unintended environmental consequence of this hydrogen sulfide emission?

- (A) Hydrogen sulfide combines with atmospheric moisture to form sulfuric acid, contributing to acid precipitation
- (B) Hydrogen sulfide reduces the efficiency of the turbines by corroding metal components
- (C) Hydrogen sulfide emissions prevent the reinjection of cooled water back into underground reservoirs
- (D) Hydrogen sulfide emissions increase the temperature of underground reservoirs, accelerating heat depletion

**Answer: (A)** Recognizing that H₂S emissions create secondary environmental impacts requires understanding atmospheric chemistry and pollution pathways. The EK identifies H₂S release as an environmental effect of geothermal use; this question extends that to trace the unintended consequence—acid rain formation—which damages ecosystems and infrastructure beyond the immediate emission site. This demonstrates how even renewable energy solutions create pollution problems.

### Question 10

Researchers monitored noise levels and bird vocalizations at a wind farm site. Data show: Distance 0.5 km from turbines: 75 decibels (dB) ambient noise, 12 bird vocalizations/hour; Distance 1 km: 68 dB, 28 vocalizations/hour; Distance 2 km: 62 dB, 45 vocalizations/hour; Distance 4 km: 58 dB, 52 vocalizations/hour. Which conclusion about wind turbine noise and bird behavior is best supported by these data?

- (A) Elevated noise levels near wind turbines correlate with reduced bird vocalization rates, suggesting that turbine noise may interfere with bird communication and behavior.
- (B) Bird vocalizations increase with distance from turbines because birds prefer to live in quieter environments, proving that wind farms cause permanent bird habitat loss.
- (C) Noise levels and bird vocalizations are unrelated because the relationship between them is not perfectly linear across all distances.
- (D) The data prove that wind turbines produce 75 decibels of noise, which is the only factor affecting bird behavior in the region.

**Answer: (A)** The data show a clear inverse relationship: as distance from turbines increases and noise decreases (75 dB to 58 dB), bird vocalizations increase (12 to 52 calls/hour). This pattern supports the conclusion that wind turbine noise suppresses bird vocalization, which could affect communication, mate attraction, and territorial behavior. This directly addresses the learning objective by identifying a specific environmental mechanism through which wind energy affects wildlife.

## Review the Unit

- [7.1 Introduction to Air Pollution](/ap-enviro/unit-7/intro-air-pollution/study-guide/eciWz0AkkBZXeKAIGiRw)
- [7.2 Photochemical Smog](/ap-enviro/unit-7/photochemical-smog/study-guide/PWfwfAuylO1PBZeNUKkD)
- [7.3 Thermal Inversion](/ap-enviro/unit-7/thermal-inversion/study-guide/ce59eexgwIH6eJTg5c3s)
- [7.4 Atmospheric CO2 and Particulates](/ap-enviro/unit-7/atmospheric-co2-particulates/study-guide/qnFJJhEN9OaY8vqVZBSb)
- [7.5 Indoor Air Pollutants](/ap-enviro/unit-7/indoor-air-pollutants/study-guide/y1B4lwSL0xpAcpSCHRjj)
- [7.6 Reduction of Air Pollutants](/ap-enviro/unit-7/reduction-air-pollutants/study-guide/7spn2Jg3SqXQN7TAPQB5)
- [7.7 Acid Rain](/ap-enviro/unit-7/acid-rain/study-guide/D55YvaAh5s6AUZHOxsER)
- [7.8 Noise Pollution](/ap-enviro/unit-7/noise-pollution/study-guide/55a1ghLYJsx9vOJFcYid)

## Other Unit Tests

- [Unit 1: The Living World: Ecosystems](/ap-enviro/unit-test/1)
- [Unit 2: The Living World: Biodiversity](/ap-enviro/unit-test/2)
- [Unit 3: Populations](/ap-enviro/unit-test/3)
- [Unit 4: Earth Systems & Resources](/ap-enviro/unit-test/4)
- [Unit 5: Land & Water Use](/ap-enviro/unit-test/5)
- [Unit 6: Energy Resources & Consumption](/ap-enviro/unit-test/6)
- [Unit 8: Aquatic & Terrestrial Pollution](/ap-enviro/unit-test/8)
- [Unit 9: Global Change](/ap-enviro/unit-test/9)

## About This Document

Canonical Fiveable pages are available as Markdown at the same path plus `.md`.

- [llms.txt](https://fiveable.me/llms.txt): index of Fiveable's sections and URL patterns
- [llms-full.txt](https://fiveable.me/llms-full.txt): complete subject and unit listing
- [MCP server](https://fiveable.me/mcp): call Fiveable as tools instead of fetching pages (`https://fiveable.me/api/mcp`)
- [MCP server for AP teachers](https://fiveable.me/mcp/teachers): a teacher's classes, assignments and AP-rubric grading (`https://fiveable.me/api/mcp/teacher`)