chem spec triple

    Cards (41)

    • how much nitrogen is in the earths' atmosphere today?

      78%
    • how much oxygen is in the earth's atmosphere today?
      21%
    • what other gases can be found in the earths atmosphere?
      carbon dioxide, water vapour, noble gases
    • why is the evidence of the early atmosphere limited?
      because of the timescale of 4.6 billion years.
    • what events released gases during the first billion years of earths existence, and what did they form?
      intense volcanic activity released gases that formed the earths early atmosphere and water vapour.
    • what condensed to form the worlds oceans?

      water vapour.
    • what other atmospheres was earths' similar to and why?
      mars & venus - they consisted of mainly co2 with little to no oxygen.
    • give one example of a gas produced by volcanoes
      nitrogen- this gradually built up in the atmosphere
      small proportions of methane and ammonia
    • what happened to co2 when oceans formed?

      it dissolved in the water and got locked up in sedimentary rocks- reducing the amount in the atmosphere
    • what produced the oxygen now in the atmosphere and how?
      algae and plants via photosynthesis
    • what is the equation for photosynthesis?

      6CO2 + 6H2O + -> C6H12O6 + 6O2
    • what is the word equation for photosynthesis?

      carbon dioxide + water ->glucose + oxygen
    • when did algae first begin to produce oxygen?

      2.7 billion years ago.
    • how did the evolution of plants help animals?

      since plants began to evolve, the percentage of oxygen gradually increased to a level that enabled animals to evolve.
    • how did plants/algae decrease the percentage of carbon dioxide?

      photosynthesis
    • what is a second way that carbon dioxide decreased?

      the formation of sedimentary rocks and fossil fuels that contain carbon
    • Explain how deposits of limestone, coal, crude oil and natural gas formed?
      • When the oceans formed, carbon dioxide dissolved in the water.
      • Dissolved CO2 went through a series of reactions to form carbonate precipitates. When marine organisms evolved, their shells and skeletons contained calcium carbonate.
      • When they died, they fell to the seabed and were buried with sediment, becoming compressed over millions of years to form sedimentary rocks (limestone + coal), crude oil and natural gas.
    • what are greenhouse gases?

      gases that act as an insulating layer in the earths atmosphere, allowing the earth to be warm enough to support life.
    • name 3 greenhouse gases
      methane
      carbon dioxide
      water vapour
    • What type of radiation does the Sun emit that hits the Earth's surface?

      Short-wavelength radiation
    • What happens to short-wavelength radiation after it hits the Earth's surface?

      It is reradiated back as long-wavelength radiation
    • How do greenhouse gases affect long-wavelength radiation?

      They absorb and reradiate it in all directions
    • What type of radiation is long-wavelength radiation?
      Thermal radiation
    • What is the result of thermal radiation on the Earth's surface?

      It results in the heating of the Earth's surface
    • How does the greenhouse effect relate to global heating?

      It disrupts the heat balance of the Earth
    • What are two human activities that increase methane levels in the atmosphere?

      Agriculture and waste decomposition
    • What is one way farm animals contribute to methane production?

      Through digestive processes
    • Name three human activities that increase carbon dioxide levels in the atmosphere.
      Deforestation, burning fossil fuels, waste decomposition
    • How does deforestation contribute to increased carbon dioxide levels?

      It reduces CO2 absorption and releases CO2
    • What happens to vegetation during deforestation that affects CO2 levels?

      Combustion and decay release CO2
    • Why do humans deforest land?

      To create space for crops and farm animals
    • Why is there skepticism about human-caused climate change?

      Modeling climate change is complex and difficult
    • What can lead to misrepresentation of climate change in media?

      Simplified models and biased opinions
    • What is a major cause of climate change?
      An increase in average global temperature
    • Describe one potential effect of global climate change.
      Sea level rise and coastal erosion
    • How does global climate change affect rainfall patterns?
      It changes rainfall patterns affecting food production
    • What is one consequence of increased storm frequency due to climate change?

      Increased severity of storms
    • How does global climate change impact biodiversity?
      It leads to a reduction in biodiversity
    • What changes in animal behavior can result from climate change?

      Changes in migration patterns and species distribution
    • What are the potential effects of global climate change?

      • Sea level rise
      • Changes in rainfall patterns
      • Increased frequency and severity of storms
      • Reduction in biodiversity
      • Changes in animal migration patterns