HS Environmental Science practice questions and exam guide

Acid rain results from:

1. Volcanic activity only
2. Carbon dioxide alone
3. Salt in air
4. Sulfur dioxide (SO₂) and nitrogen oxides (NOx) — from fossil fuel burning — reacting with atmospheric water to form sulfuric and nitric acids; damages lakes, forests, buildings
5. Sun heat

Answer: D — Sulfur dioxide (SO₂) and nitrogen oxides (NOx) — from fossil fuel burning — reacting with atmospheric water to form sulfuric and nitric acids; damages lakes, forests, buildings

Acid rain: pH < 5.6. Major problem in 1970s-80s NE US/Canada from Midwest coal plants. Damaged forests (e.g., Adirondacks), lakes. Clean Air Act amendments (1990) cap-and-trade program for SO₂ very successful. Acid rain largely solved problem.

Which of the following is the primary mechanism by which greenhouse gases warm Earth?

1. Reflecting incoming sunlight back into space
2. Absorbing and re-radiating outgoing infrared (long-wave) radiation, trapping heat in the lower atmosphere
3. Blocking ultraviolet light from reaching the surface
4. Generating new heat through chemical reactions

Answer: B — Absorbing and re-radiating outgoing infrared (long-wave) radiation, trapping heat in the lower atmosphere

B) Greenhouse effect mechanism. A) Albedo (cooling). C) Ozone's role. D) Not how GHGs work.

Biogeochemical cycles include:

1. Carbon, nitrogen, phosphorus, water, sulfur, oxygen — recycle elements through atmosphere, biosphere, hydrosphere, lithosphere
2. Only carbon
3. Random
4. No cycles

Answer: A — Carbon, nitrogen, phosphorus, water, sulfur, oxygen — recycle elements through atmosphere, biosphere, hydrosphere, lithosphere

A) Standard. B/C/D) Each is incomplete.

The greenhouse effect is:

1. Always harmful
2. Has no effect
3. Cooling
4. The natural warming of Earth's surface caused by certain atmospheric gases (CO₂, CH₄, water vapor) absorbing and re-radiating infrared energy — essential for habitable temperatures; human-enhanced concentrations cause additional warming (climate change)

Answer: D — The natural warming of Earth's surface caused by certain atmospheric gases (CO₂, CH₄, water vapor) absorbing and re-radiating infrared energy — essential for habitable temperatures; human-enhanced concentrations cause additional warming (climate change)

D) Defining concept. A/B/C) Each is incorrect.

Ex-situ conservation refers to:

1. Habitat restoration in the wild
2. Protecting species in their natural habitat through reserves
3. Conserving species outside their natural habitat (zoos, botanical gardens, seed banks)
4. Releasing invasive species to compete with natives

Answer: C — Conserving species outside their natural habitat (zoos, botanical gardens, seed banks)

C) Ex-situ = off-site (zoos, seed banks). B) In-situ conservation. A) A specific in-situ technique. D) Not conservation.

Plastic pollution:

1. Only paper waste
2. Persistent waste accumulating in oceans (gyres like Great Pacific Garbage Patch), entangling/being ingested by wildlife; microplastics in food chain; single-use plastics major source
3. Easily decomposes
4. Just landfills
5. Beneficial waste

Answer: B — Persistent waste accumulating in oceans (gyres like Great Pacific Garbage Patch), entangling/being ingested by wildlife; microplastics in food chain; single-use plastics major source

Plastic pollution: ~11M tonnes enter oceans/yr. Photodegrades to microplastics (everywhere — Arctic ice, deep ocean, human blood). Wildlife harm. Some progress: bans on bags/microbeads, EPR (extended producer responsibility) policies, recycling.

Green building:

1. Design and construction reducing environmental impact — energy efficiency (insulation, windows, LED), water efficiency, sustainable materials, indoor air quality, site impact; certifications (LEED, Energy Star) provide standards; lower lifetime costs
2. Has no role
3. Costs more forever
4. Random

Answer: A — Design and construction reducing environmental impact — energy efficiency (insulation, windows, LED), water efficiency, sustainable materials, indoor air quality, site impact; certifications (LEED, Energy Star) provide standards; lower lifetime costs

A) Standard. B/C/D) Each is incorrect.

Biodiversity hotspots are valued because they:

1. Hold the world's wealthiest cities
2. Are always cold deserts
3. Contain many endemic species under threat — protecting them preserves a large share of global biodiversity
4. Have no native species at all

Answer: C — Contain many endemic species under threat — protecting them preserves a large share of global biodiversity

C) Conservation-International criterion. A/B/D) Each contradicts the definition.

In the waste management hierarchy, the LEAST preferred option is:

1. Source reduction (reduce)
2. Reuse
3. Recycling and composting
4. Disposal in landfills or incineration without energy recovery

Answer: D — Disposal in landfills or incineration without energy recovery

D) Bottom of hierarchy. A/B/C) Higher-priority options.

An ecosystem consists of:

1. Only the living organisms in an area
2. Only the non-living components of an area
3. All living organisms and their physical environment interacting as a system
4. A single species and its predators

Answer: C — All living organisms and their physical environment interacting as a system

An ecosystem includes both biotic (living) and abiotic (non-living) components and their interactions.

The Kyoto Protocol (1997) differed from the Paris Agreement (2015) primarily in that Kyoto:

1. Required developing nations to cut emissions more than developed ones
2. Was never adopted
3. Was led by China alone
4. Set binding emissions reduction targets only for developed (Annex I) countries, while Paris uses nationally determined contributions (NDCs) from all parties

Answer: D — Set binding emissions reduction targets only for developed (Annex I) countries, while Paris uses nationally determined contributions (NDCs) from all parties

D) Standard distinction — Kyoto's top-down binding cuts vs Paris's universal voluntary NDCs. A/B/C) Incorrect.

Acid rain is most commonly caused by:

1. Methane emissions from livestock
2. Sulfur dioxide and nitrogen oxide emissions reacting with water in the atmosphere
3. Carbon dioxide alone
4. Volcanic ash

Answer: B — Sulfur dioxide and nitrogen oxide emissions reacting with water in the atmosphere

SO₂ and NOₓ emissions (mainly from burning coal and vehicle exhaust) react with atmospheric water to form sulfuric and nitric acids.

Sustainable agriculture practices?

Crop rotation, cover crops, integrated pest management, no-till, organic.

Solar pros and cons?

Pros: clean, free fuel, distributable. Cons: intermittent, manufacturing impacts, requires storage/grid integration.

Personal actions for environment?

Reduce energy, walk/bike/transit, eat less meat, reduce waste, support conservation, vote.

Ecosystem?

Community of organisms + their physical environment, interacting.

Population pyramid?

Graph showing age + sex distribution. Shape indicates demographics.

Worked example — Radioactive half-life: Plutonium-239 has a half-life of ~24,000 years. If a sample contains 800 g today, how much remains after 72,000 years (assuming no removal)?

Step 1 — Find number of half-lives: 72,000 ÷ 24,000 = 3 half-lives. Step 2 — Apply halving: 800 → 400 (1) → 200 (2) → 100 g (3). Step 3 — Interpret: 100 g remains after 72,000 years. This is why high-level nuclear waste storage must be secure for hundreds of thousands of years — a key challenge for nuclear power.