Topic 9 - Chemistry of the atmosphere

• What is the approximate percentage of nitrogen in the modern atmosphere?

  Around 80%
• What is the approximate percentage of oxygen in the modern atmosphere?

  Around 20%
• What gases are present in small quantities in the modern atmosphere?

  CO2, H2O, and noble gases
• How was the Earth's early atmosphere formed?

  Through significant volcanic activity releasing gases
• What was the state of the Earth when it was formed?

  The Earth was hot
• What gases were released from early volcanic activity?

  CO2, N2, CH4, NH3, H2O
• How did the amount of oxygen in the atmosphere increase?

  Through photosynthesis by algae and plants
• What is the photosynthesis equation that produces oxygen?

  6 CO2 + 6 H2O → C6H12O6 + 6 O2
• What happens to carbon dioxide in the oceans?

  It reacts with metal ions to form carbonates
• How does carbon dioxide become part of animal skeletons?

  Animals take in CO2, forming skeletons
• What happens to carbon dioxide when animals die?

  It becomes part of sedimentary rock
• What is the greenhouse effect?

  It maintains Earth's temperature for life
• Why is the greenhouse effect necessary for life?

  It prevents Earth from being too cold
• How have human activities increased greenhouse gases?

  Through combustion and deforestation
• What are potential effects of global climate change?

  Sea level rise and severe storms
• What is a carbon footprint?

  • Total amount of CO2 emitted
  • Includes other greenhouse gases
  • Measured over the life cycle of a product
• What actions can reduce a carbon footprint?

  • Use alternative energy supplies
  • Energy conservation
  • Carbon capture and storage
  • Implement carbon taxes and licenses
  • Engage in carbon offsetting
  • Achieve carbon neutrality
• What are the problems of reducing the carbon footprint?

  • Scientific disagreement on climate change
  • Lack of public information and education
  • Resistance to lifestyle changes
  • Economic considerations
  • Incomplete international cooperation
• What are the advantages of complete combustion?

  • Less soot produced
  • More heat released per gram
  • No poisonous carbon monoxide produced
• How is pollution caused by combustion?

  Gases like CO2 and SO2 are released
• What issues are associated with sulfur dioxide and oxides of nitrogen?

  They cause respiratory problems and acid rain
• What problems do particulates cause?

  They cause global dimming and health issues