pollutants, elements, greenhouse gases, hydrocarbons, and other relevant terms for AP Environmental Science (APES).

Pollutants

1. Sulfur Dioxide (SO₂)

   • Definition: A colorless, corrosive gas that is primarily produced by the burning of coal and oil, especially in power plants.

   • Impact: Causes respiratory issues, acid rain formation, and damages plant life.

2. Nitrogen Oxides (NOx)

   • Definition: Gases (NO and NO₂) produced during the combustion of fossil fuels (e.g., in vehicles, industrial processes).

   • Impact: Contributes to smog, acid rain, and respiratory problems.

3. Carbon Monoxide (CO)

   • Definition: A colorless, odorless gas produced by the incomplete combustion of fossil fuels.

   • Impact: Harmful to human health by reducing oxygen delivery in the bloodstream.

4. Particulate Matter (PM)

   • Definition: Tiny solid particles or droplets in the air (PM10, PM2.5), which include dust, soot, and liquid droplets.

   • Impact: Can cause respiratory and cardiovascular diseases and contribute to haze and smog.

5. Volatile Organic Compounds (VOCs)

   • Definition: Organic chemicals that easily evaporate into the air (e.g., gasoline vapors, solvents).

   • Impact: Contribute to ozone formation and smog, harmful to human health.

6. Ozone (O₃)

   • Definition: A reactive molecule made up of three oxygen atoms; in the stratosphere, it protects against UV radiation; in the troposphere, it is a pollutant.

   • Impact: In the troposphere, it is a key component of photochemical smog and causes respiratory issues.

7. Lead (Pb)

   • Definition: A heavy metal that can be released into the air through industrial processes or from old gasoline.

   • Impact: Toxic to the nervous system, especially in children.

8. Mercury (Hg)

   • Definition: A toxic metal released into the environment from coal combustion and waste incineration.

   • Impact: Accumulates in food chains (bioaccumulation) and can cause neurological damage.

Elements (Relevant to APES)

1. Carbon (C)

   • Definition: A fundamental element in all living organisms, forms carbon dioxide (CO₂) in the atmosphere.

   • Role: Major component of the carbon cycle, involved in global warming via CO₂.

2. Nitrogen (N)

   • Definition: Essential element for all living organisms, found in the atmosphere as N₂.

   • Role: Key part of the nitrogen cycle (fixation, nitrification, denitrification) for protein and DNA formation.

3. Sulfur (S)

   • Definition: Found in nature as sulfates and sulfur dioxide (SO₂), produced by volcanic eruptions and burning fossil fuels.

   • Role: Key part of the sulfur cycle; contributes to acid rain when combined with water vapor.

4. Phosphorus (P)

   • Definition: A key element for DNA, RNA, and ATP, found in rocks and soil as phosphate.

   • Role: Key part of the phosphorus cycle, often limiting nutrient for plants.

5. Potassium (K)

   • Definition: A vital nutrient for plant growth, found in soil and used in fertilizers.

   • Role: Affects plant water balance and enzyme activity.

6. Calcium (Ca)

   • Definition: A mineral found in limestone and rocks, essential for living organisms, especially in bones and shells.

   • Role: Key part of the calcium cycle, can affect soil acidity and plant growth.

Greenhouse Gases (GHGs)

1. Carbon Dioxide (CO₂)

   • Definition: A colorless, odorless gas produced by the combustion of fossil fuels and respiration.

   • Impact: Major greenhouse gas contributing to global warming by trapping heat in the atmosphere.

2. Methane (CH₄)

   • Definition: A colorless, odorless gas produced by livestock digestion (enteric fermentation), landfills, and fossil fuel extraction.

   • Impact: A potent greenhouse gas with a much higher heat-trapping potential than CO₂.

3. Nitrous Oxide (N₂O)

   • Definition: A greenhouse gas produced by agricultural activities, such as fertilizer application.

   • Impact: Contributes to global warming and ozone depletion.

4. Water Vapor (H₂O)

   • Definition: A naturally occurring gas in the atmosphere that amplifies global warming by increasing with rising temperatures.

   • Impact: Not directly controlled by humans, but contributes to the greenhouse effect.

5. Ozone (O₃)

   • Definition: Found in both the stratosphere (good ozone) and troposphere (bad ozone). Forms from nitrogen oxides (NOx) and volatile organic compounds (VOCs).

   • Impact: In the troposphere, it is a greenhouse gas contributing to warming and pollution; in the stratosphere, it protects from harmful UV radiation.

6. Chlorofluorocarbons (CFCs)

   • Definition: Synthetic compounds used in refrigerants and aerosol propellants.

   • Impact: Extremely potent greenhouse gases; also responsible for ozone depletion.

Hydrocarbons

1. Methane (CH₄)

   • Definition: The simplest hydrocarbon, a colorless and odorless gas that is a key component of natural gas.

   • Impact: Powerful greenhouse gas; contributes to global warming.

2. Propane (C₃H₈)

   • Definition: A gaseous hydrocarbon used as a fuel for heating and cooking.

   • Impact: When burned, it releases carbon dioxide, a greenhouse gas.

3. Butane (C₄H₁₀)

   • Definition: A hydrocarbon found in natural gas and used in fuel canisters.

   • Impact: When burned, it produces carbon dioxide and other pollutants.

4. Benzene (C₆H₆)

   • Definition: A volatile organic compound and hydrocarbon, commonly used in industrial processes.

   • Impact: Toxic and a known carcinogen; can contribute to air pollution.

5. Toluene (C₇H₈)

   • Definition: A hydrocarbon used in paint thinners, adhesives, and other industrial chemicals.

   • Impact: Toxic; contributes to air pollution and is harmful to human health.

Other Relevant Terms

1. Acid Rain

   • Definition: Rainfall that is unusually acidic (pH < 5.6) due to the presence of sulfuric acid (H₂SO₄) and nitric acid (HNO₃) formed from sulfur dioxide (SO₂) and nitrogen oxides (NOx).

   • Impact: Damages ecosystems, buildings, and human health.

2. Eutrophication

   • Definition: The process by which a body of water becomes enriched with excess nutrients (especially nitrogen and phosphorus).

   • Impact: Causes algal blooms, which reduce oxygen levels, harming aquatic life.

3. Smog

   • Definition: A type of air pollution caused by a combination of smoke and fog, often involving ground-level ozone (tropospheric ozone).

   • Impact: Causes respiratory problems and reduced visibility.