ATMOSPHERE

• Atmosphere

  The layer of gases surrounding the Earth that is retained by Earth's gravity
• Nitrogen is the most abundant gas in Earth's atmosphere- TRUE
• Stratosphere

  The layer of the atmosphere known for containing the ozone layer
• Greenhouse gases

  Gases that trap heat and warm the planet
• Ozone layer

  Shields the Earth from harmful UV radiation
• Oxygen gives the sky its blue color- FALSE
• Photosynthesis by plants is the main source of oxygen in the Earth's atmosphere- TRUE
• Troposphere

  The layer of the atmosphere closest to the Earth's surface
• The average composition of Earth's atmosphere by volume is 78% nitrogen, 21% oxygen, 1% other gases- TRUE
• Carbon dioxide is a greenhouse gas that contributes to climate change- TRUE
• Roles of the atmosphere in protecting life on Earth

  • Absorbing sunlight
  • Regulating temperature
  • Filtering pollutants