Science- earth- chemistry Y8

• what does recycling mean?


  The process of changing waste materials into something useful
• What is a landfill?


  Waste disposal site.
• What can be recycled?


  Paper, plastic, glass, metal.
• Advantages of recycling:

  • Sustainable alternative
  • less waste sent to landfills
  • less pollution
  • less release of greenhouse gas
• Gas


  The mixture of gases around the Earth
• Atmosphere


  The mixture of gases around the Earth
• Gases in the atmosphere


  • Nitrogen
  • Oxygen
  • Argon
  • Carbon dioxide
  • Water vapour
  • Other gases
• Nitrogen is the most abundant gas, followed by oxygen. These two make up around 99% of the atmosphere
• The Earth's atmosphere has been similar for the past 200 years
• Combustion


  Reaction of fuels with oxygen that transfers thermal energy to the surroundings
• The two products of combustion are water and carbon dioxide
• A candle is not put in a fully enclosed container because it needs oxygen to burn
• Cobalt paper turns pink and limewater turns cloudy as positive results for testing for carbon dioxide
• Carbon cycle


  The way in which carbon atoms pass between living organisms and their environment
• Carbon stores


  Ways of storing carbon so it isn't in the atmosphere
• Minerals


  Chemicals from which rocks are made
• Vegetation


  Plants (collectively)
• Photosynthesis


  Process carried out by green plants - uses sunlight, carbon dioxide and water to produce glucose and oxygen
• How a carbon atom travels around the world

  1. Live plant

  2. Dead plant

  3. Eaten by animal

  4. Respiration releases CO2

  5. Photosynthesis traps CO2

  6. Combustion of fossil fuels releases CO2
• Producers are organisms like plants that use carbon dioxide to make glucose
• Decomposers like bacteria and fungi break down dead organisms and release the carbon they contain
• Humans have accelerated the release of carbon into the atmosphere through burning fossil fuels, deforestation, and other activities
• Humans have reduced carbon release through planting trees, using renewable energy, and other methods
• Global warming


  Rise in global mean temperature caused by increased greenhouse gases in the atmosphere
• Effects of global warming


  • Polar ice sheets melting, causing sea level rise and habitat loss
  • Some areas having less water, causing drought and food shortages
  • Longer growing seasons and faster crop growth due to increased CO2
  • Severe weather events
  • Spread of tropical diseases
  • Thriving of agricultural pests
• Greenhouse effect


  The trapping of the Sun's infrared radiation by the Earth's atmosphere
• Concentration


  Amount of something per unit volume
• Greenhouse gas


  A gas responsible for the greenhouse effect
• Carbon emissions


  The amount of carbon released from an action or device
• Deforestation


  Cutting or burning down trees
• Natural resource


  Material that occurs in nature that can be put to use
• Renewable resource


  A resource that will not run out, e.g. solar and wind energy
• Non-renewable resource


  A resource that cannot be renewed in our lifetime, e.g. coal, oil and gas
• Sustainable


  Using a resource or process in such a way that it will be available to future generations
• The Earth's natural resources include biological resources (plants and animals), land, fossil fuels, water, and metal ores
• Renewable resources include the Sun's energy, wind, tides, and geothermal heat
• Pollution is produced as we process natural resources
• Downcycling


  Loss of viability or value in a product as it is recycled
• Pollution


  Substances that are harmful to the environment if released
• Hygiene


  Being clean to maintain health