atmosphere

• How long ago did the Earth form?

  ~4.6 billion years ago
• What caused the early atmosphere to form?

  Intense volcanic activity released gases
• What was the primary gas in the early atmosphere?

  Carbon dioxide (CO₂)
• Which planets have atmospheres similar to the early Earth?

  Venus and Mars
• What other gases were present in the early atmosphere?

  Water vapour, methane, ammonia, nitrogen
• What was the state of life on Earth during the early atmosphere phase?

  No life existed
• What happened to the Earth around 3.8 billion years ago?

  The Earth cooled and formed oceans
• What did marine organisms use to form calcium carbonate shells?

  Dissolved CO₂
• What significant event occurred around 2.7 billion years ago?

  First photosynthetic bacteria and algae evolved
• What is the chemical equation for photosynthesis?

  6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
• How did oxygen levels change over time?

  Oxygen levels increased over time
• What happened to CO₂ levels as oxygen levels increased?

  CO₂ levels decreased
• What formed as CO₂ became locked in over time?

  Fossil fuels and sedimentary rocks
• What is the role of the ozone layer?

  Protects Earth from harmful UV radiation
• What is the current composition of the atmosphere?

  • Nitrogen (N₂): 78%
  • Oxygen (O₂): 21%
  • Argon (Ar): 0.9%
  • Carbon Dioxide (CO₂): 0.04%
  • Other gases: Trace amounts
• What is the function of greenhouse gases?

  Trap heat in the atmosphere
• What are the main greenhouse gases?

  CO₂, CH₄, H₂O
• How does the greenhouse effect work?

  Greenhouse gases absorb and trap heat
• What human activity increases CO₂ levels?

  Burning fossil fuels
• What are the consequences of climate change?

  Melting ice caps and rising sea levels
• What is one effect of ocean acidification?

  Harms aquatic life
• What are some ways to reduce climate change?

  • Use renewable energy (solar, wind)
  • Improve energy efficiency
  • Reforestation to absorb CO₂
  • Reduce waste and recycle
• What is a major source of carbon monoxide (CO)?

  Incomplete combustion of fuels
• What are the effects of particulates from burning fuels?

  Causes respiratory problems
• What causes acid rain?

  SO₂ and NOx dissolving in water
• What is one way to reduce air pollution?

  Use catalytic converters in cars
• What is a carbon footprint?

  Total amount of CO₂ emitted
• How can individuals reduce their carbon footprint?

  Use public transport and electric vehicles
• What are the Kyoto Protocol and Paris Agreement?

  • International treaties to reduce CO₂ emissions
  • Aim to limit global warming below 1.5°C
  • Encourage renewable energy sources
• What is carbon capture and storage (CCS)?

  Captures CO₂ and stores it underground
• What are the pros and cons of alternative fuels?

  Pros:

  • Renewable and less CO₂
  • Only emits water (hydrogen fuel)
  • No emissions (electric cars)

  
  

  Cons:

  • Uses land for crops (biofuels)
  • Difficult to store (hydrogen fuel)
  • Batteries require mining (electric cars)
• What is the role of green chemistry in sustainability?

  • Reduces waste and energy use
  • Develops biodegradable plastics
  • Creates efficient catalysts
• What are some sustainable manufacturing practices?

  • Recycling metals saves energy
  • Using renewable materials reduces impact
  • Desalination provides fresh water
• What are the key ideas about the atmosphere?

  • Evolved from volcanic gases and photosynthesis
  • Greenhouse gases trap heat, increased by humans
  • Air pollution harms health and environment
  • Solutions include renewable energy and recycling