chemistry of the atmosphere

• How have oxygen levels changed from the early to modern atmosphere?

  Oxygen levels have increased.
• What has happened to carbon dioxide and water vapor levels from the early to modern atmosphere?

  Carbon dioxide and water vapor levels have decreased.
• What has happened to nitrogen levels from the early to modern atmosphere?

  Nitrogen levels have increased.
• Why were carbon dioxide levels high in the early atmosphere?

  Due to lots of volcanic activity.
• What process is responsible for the change in oxygen and carbon dioxide levels?

  Photosynthesis.
• What do plants take in and release during photosynthesis?


  They take in carbon dioxide and release oxygen.
• When did the change in oxygen levels occur?

  When green algae started growing in the oceans.
• How does the sea contribute to reducing carbon dioxide levels?

  The sea acts as a store for carbon dioxide.
• What caused the decrease in water vapor levels?

  The cooling of the Earth.
• What happened to water vapor as the Earth's temperature decreased?

  It condensed and fell as rain.
• What are the main components of the carbon cycle?

  • Plants get energy from food.
  • Carbon dioxide is a waste product.
  • Plants use carbon dioxide and water.
  • Fuels like wood and oil release carbon dioxide.
  • Methane burns to produce carbon dioxide and water.
  • Photosynthesis converts carbon dioxide and water into glucose and oxygen.
  • Oceans remove carbon dioxide from the atmosphere.
• What is the main source of nitrogen in the atmosphere?

  Volcanic eruptions.
• Why has nitrogen concentration built up in the atmosphere?

  It is unreactive and not removed.
• What percentage of the air is nitrogen now?

  Around 78%.
• How do plants contribute to the carbon cycle?

  • Absorb carbon dioxide during photosynthesis.
  • Convert carbon dioxide into glucose.
  • Release oxygen as a byproduct.
• What happens to carbon when animals eat plants?

  Carbon is transferred into the animal's tissue.
• How are carbonate rocks formed over millions of years?

  • Skeletons/shells of marine organisms build up.
  • Covered with fine sediment.
  • Under pressure, they become carbonate rocks (limestone).
• What is the chemical formula for calcium carbonate?

  $CaCO_3$
• How are fossil fuels formed?

  From remains of plants deposited in mud.
• What is coal made from?

  Plants that contained carbon.
• What do crude oil and natural gases lock in them?

  Carbon from plankton.
• What is the reaction for testing carbonates in rocks?

  $calcium carbonate +$$hydrochloric acid → calcium chloride +$$carbon dioxide +$$water$
• What is the reaction for testing carbon dioxide?

  $CO_2 +$$Ca(OH)_2 → CaCO_3 +$$H_2O$
• What are the main processes that add and remove carbon dioxide from the atmosphere?

  Add carbon dioxide:

  • Respiration
  • Combustion

  
  

  Remove carbon dioxide:

  • Photosynthesis
  • Oceans
• What is the greenhouse effect?

  Gases trap heat in the atmosphere.
• What happens to infrared radiation from the Earth?

  It struggles to escape back into space.
• What role did the natural greenhouse effect play before the industrial revolution?


  It was important for life to survive.
• What contributes to global warming besides carbon dioxide?

  Methane released from cattle and landfills.
• What is a carbon footprint?

  • Total set of greenhouse gases caused directly or indirectly.
  • By an individual, organization, event, or product.
• What are soot/carbon particles and their effects?

  They trigger asthma and cause global dimming.
• What is carbon monoxide and its effects?

  It is toxic and binds to hemoglobin.
• What causes acid rain?

  Sulfur oxides reacting with air.
• What are the effects of acid rain?

  • Damages buildings and materials.
  • Kills/damages trees.
  • Poisons fish by dissolving aluminum.
• What is global dimming and its effects?

  • Solid particles in the atmosphere block sunlight.
  • Causes a cooling effect.
  • Triggers asthma and blackens buildings.
• How can we reduce the effects of global dimming?

  Ensure enough oxygen for combustion.