Chemistry of the atmosphere

• What is the time period over which the Earth's atmosphere has evolved?

  1. 6 billion years
• What was the primary source of gases in the early Earth's atmosphere?

  • Volcanic eruptions released gases
  • Early atmosphere was mostly carbon dioxide
  • Similar to Mars and Venus today
• What gases were released by volcanic activity in the early atmosphere?

  Nitrogen, water vapour, methane, and ammonia
• How did oceans form in the early Earth?

  Water vapour in the atmosphere condensed to form oceans
• What happened to carbon dioxide in the early oceans?

  It dissolved in the oceans and formed carbonate precipitates
• What process do green plants and algae use to absorb carbon dioxide?

  Photosynthesis
• What happened to the carbon from dead organisms over time?

  It became locked up in rocks and fossil fuels
• What are fossil fuels and how are they formed?

  • Fossil fuels include coal, crude oil, and natural gas
  • Formed from the remains of dead plants and animals
  • Compressed over millions of years under sediment
• What is coal primarily made from?

  Thick plant deposits
• What is limestone primarily composed of?

  Calcium carbonate deposits
• What is the chemical equation for photosynthesis?

  carbon dioxide + water → glucose + oxygen
• What is the significance of oxygen levels building up in the atmosphere?

  It allowed more complex life forms to evolve
• What is the approximate composition of the atmosphere today?

  80% nitrogen, 20% oxygen, and small amounts of other gases
• What role do greenhouse gases play in the Earth's atmosphere?

  • Act as an insulating layer
  • Keep the Earth warm enough to support life
  • Include carbon dioxide, methane, and water vapour
• How do greenhouse gases contribute to the greenhouse effect?

  They absorb long wavelength radiation and re-radiate it back to Earth
• What human activities increase greenhouse gas levels?

  Deforestation, burning fossil fuels, agriculture, and waste creation
• What is the relationship between increased carbon dioxide and climate change?

  Extra carbon dioxide from human activity is causing temperature increases
• Why is it difficult to fully understand the Earth's climate?

  Because it is complex with many variables
• What are some potential consequences of climate change?

  Melting polar ice caps, changes in rainfall patterns, and increased storm severity
• What is a carbon footprint?

  • Measure of carbon dioxide and greenhouse gases released
  • Can apply to services, events, products, etc.
  • Difficult to measure accurately due to many factors
• What are some methods to reduce carbon footprints?

  Using renewable energy, efficient processes, and government regulations
• Why is it challenging to implement reductions in carbon emissions?

  Concerns about economic growth and lack of international cooperation
• What gases are released during the combustion of fossil fuels?

  Carbon dioxide, water vapour, nitrogen oxides, and sulfur dioxide
• What is complete combustion?

  When there is plenty of oxygen and all fuel burns
• What are the effects of particulates released during incomplete combustion?

  They can cause respiratory problems and contribute to global dimming
• Why is carbon monoxide dangerous?

  It binds to haemoglobin, reducing oxygen transport in the blood
• What is sulfur dioxide released from?

  Combustion of fossil fuels containing sulfur impurities
• What happens when nitrogen oxides mix with clouds?

  They form dilute nitric acid, leading to acid rain
• What are the effects of acid rain?

  It kills plants, damages buildings, and causes metal corrosion
• What health issues can sulfur dioxide and nitrogen oxides cause?

  They can cause respiratory problems when inhaled