Air Pollution and Atmospheric Issues — HS Environmental Science practice questions

A catalytic converter in a car reduces:

1. carbon dioxide emissions from the exhaust
2. the amount of fuel the engine burns
3. noise from the engine
4. carbon monoxide, NOₓ, and unburned fuel

Answer: D — carbon monoxide, NOₓ, and unburned fuel

D) Correct — It converts them to CO₂, N₂, and water. A) It actually produces CO₂ from CO. B) It cleans exhaust; it does not save fuel. C) A muffler reduces noise.

The U.S. Clean Air Act gives the EPA power to:

1. clean up abandoned toxic sites
2. set limits on major air pollutants
3. protect endangered species
4. regulate drinking water

Answer: B — set limits on major air pollutants

B) Correct — It regulates pollutants such as ozone, PM, SO₂, and lead. A) Is the Superfund law. C) Is the Endangered Species Act. D) Is the Safe Drinking Water Act.

The main human cause of stratospheric ozone depletion was:

1. carbon dioxide
2. CFCs
3. sulfur dioxide
4. methane

Answer: B — CFCs

B) Correct — Chlorine from CFCs breaks apart ozone molecules. A) Causes warming, not ozone depletion. C) Causes acid rain. D) Is a greenhouse gas.

Acid rain is formed mainly from:

1. carbon dioxide alone
2. sulfur dioxide and nitrogen oxides
3. methane and water vapor
4. ozone and CFCs

Answer: B — sulfur dioxide and nitrogen oxides

B) Correct — They react with water to form sulfuric and nitric acids. A) Makes rain only slightly acidic. C) Are greenhouse gases. D) Are linked to smog and ozone depletion.

Which is a primary air pollutant?

1. Ground-level ozone
2. Carbon monoxide from car exhaust
3. Sulfuric acid in rain
4. Photochemical smog

Answer: B — Carbon monoxide from car exhaust

B) Correct — Primary pollutants are emitted directly. A) Forms from reactions in the air. C) Forms from SO₂ reacting with water. D) Forms from reactions in sunlight.

Fine particles (PM2.5) are dangerous because they:

1. are too large to inhale
2. reach deep into the lungs
3. only affect plants
4. always come from volcanoes

Answer: B — reach deep into the lungs

B) Correct — They can enter the bloodstream and harm the heart. A) They are tiny. C) They harm human health. D) Most come from burning fuels.

Primary vs secondary air pollutants?

Primary: emitted directly (CO, SO₂, NOₓ, particulates). Secondary: form in the air from reactions (ground-level ozone, sulfuric acid).

Good ozone vs bad ozone?

Stratospheric ozone absorbs UV radiation (good). Ground-level ozone is a lung-irritating part of smog (bad).

Acid rain causes?

SO2 + NOx from burning fossil fuels → sulfuric/nitric acid in rain.

Air pollution sources?

Vehicles (cars), power plants (coal), industry, agriculture, wildfires.