Chemistry of the Atmosphere Flashcards
(21 cards)
What were the main gases in Earth’s early atmosphere?
Mostly carbon dioxide (CO₂), with little or no oxygen (O₂), and small amounts of nitrogen, water vapor, methane, and ammonia.
What caused the early atmosphere to be rich in carbon dioxide?
Volcanic activity released large amounts of CO₂ and water vapor.
How did the amount of oxygen in the atmosphere increase?
Photosynthesis by early cyanobacteria and plants produced oxygen.
How did the amount of carbon dioxide decrease?
- Dissolved in oceans and formed carbonate rocks.
- Used by photosynthesis.
- Locked up in fossil fuels.
What are the main gases in today’s atmosphere?
• 78% Nitrogen (N₂)
• 21% Oxygen (O₂)
• 0.04% Carbon Dioxide (CO₂)
• Small amounts of water vapor and noble gases (e.g., argon)
How has the level of carbon dioxide changed over time?
It has decreased significantly due to photosynthesis, formation of carbonate rocks, and fossil fuel formation.
What are greenhouse gases?
Gases that trap heat in the Earth’s atmosphere, such as carbon dioxide (CO₂), methane (CH₄), and water vapor (H₂O).
How does the greenhouse effect work?
- Short-wavelength radiation from the Sun passes through the atmosphere.
- The Earth absorbs and re-emits this energy as long-wavelength infrared radiation.
- Greenhouse gases absorb and re-radiate this heat, keeping the Earth warm.
Why is the greenhouse effect important?
It keeps the Earth warm enough to support life.
What human activities increase greenhouse gases?
• Burning fossil fuels (increases CO₂).
• Deforestation (reduces CO₂ absorption by trees).
• Agriculture (cattle and rice farming release methane).
• Landfill waste (decomposing waste releases methane).
What is climate change?
A long-term change in Earth’s temperature and weather patterns due to increased greenhouse gases.
What are the possible effects of climate change?
• Rising sea levels (due to melting ice caps and thermal expansion).
• More extreme weather (storms, droughts, and heatwaves).
• Changes in ecosystems (loss of biodiversity, habitat destruction).
• Food and water shortages due to droughts and flooding.
What are possible ways to reduce climate change?
• Use renewable energy (wind, solar, hydro).
• Increase energy efficiency (insulation, LED lights).
• Plant more trees to absorb CO₂.
• Reduce waste and recycle more.
How is carbon monoxide produced?
By the incomplete combustion of fossil fuels.
Why is carbon monoxide dangerous?
It is colorless, odorless, and toxic, preventing oxygen from binding to red blood cells, leading to suffocation.
What are particulates, and why are they harmful?
Tiny solid particles of carbon that cause global dimming and lung problems.
How is sulfur dioxide (SO₂) produced?
Burning fossil fuels that contain sulfur impurities.
What environmental problems does sulfur dioxide cause?
It dissolves in rain to form acid rain, which damages trees, buildings, and aquatic life.
How are nitrogen oxides (NOₓ) produced?
When nitrogen in the air reacts with oxygen at high temperatures in car engines.
What do nitrogen oxides cause?
Respiratory problems and acid rain.
How can we reduce sulfur dioxide emissions?
• Remove sulfur from fuels before burning.
• Use scrubbers in power stations to remove SO₂ from waste gases.
