L6

• What is electrolysis?


  A chemical process
• What percentage of the Earth's surface is covered by oceans?

  Up to 71%
• What role do oceans play in regulating the planet's climate?

  They form a continuous expanse of water that influences climate patterns
• What are the five major oceans?

  • Pacific Ocean
  • Atlantic Ocean
  • Indian Ocean
  • Arctic Ocean
  • Southern Ocean
• Which ocean is the largest and deepest?

  Pacific Ocean
• What is the area of the Pacific Ocean?

  63.8 million m² (165.25 million km²)
• Where does the Pacific Ocean stretch from and to?

  From the Arctic Ocean in the north to the Southern Ocean, and from the Americas in the east to Asia and Australia in the west
• What is the second largest ocean?

  Atlantic Ocean
• What is the area of the Atlantic Ocean?

  41.1 million m² (106.4 million km²)
• What is the role of the Atlantic Ocean in global trade?


  It serves as a major route for global trade and commerce
• What is the area of the Indian Ocean?

  28.4 million m² (73.56 million km²)
• Which continents border the Indian Ocean?


  Asia to the north, Africa to the west, Australia to the east, and the Southern Ocean
• What is the area of the Arctic Ocean?

  1. 4 million m² (14.06 million km²)
• What is the significance of the Antarctic Circumpolar Current?

  It is a powerful circumpolar current in the Arctic Ocean
• What is the oldest sea mentioned in the study material?

  Mediterranean Sea
• What is the composition of seawater?

  97% NaCl, Mg, S, Ca, K from rainfalls and rivers/streams
• What is desalination?

  Removing salts or other minerals and contaminants from seawater, brackish water, and wastewater
• What percentage of water is groundwater?

  0.9%
• How does groundwater reach the water table?

  Precipitation infiltrates into soil and percolates downward
• What is an aquifer?

  Spaces between rocks and particles filled with water below the water table
• What percentage of water do lakes represent?

  0.008%
• What is the oldest lake mentioned in the study material?

  Lake Baikal in Siberia, Russia
• What percentage of water do rivers represent?

  0.0002%
• What is the significance of rivers in the Earth's hydrological cycle?

  They are a fundamental component that shapes landscapes
• What is the oldest river mentioned in the study material?

  New River in North America
• What percentage of water is represented by ice?

  1. 06%
• Where is the oldest ice located?

  In Antarctica
• What percentage of water do wetlands represent?

  0.001%
• What are wetlands also known as?

  Deltas, estuaries, marshes, swamps, and bayous
• What is the oldest wetland mentioned in the study material?


  Marjal de Almenara in Spain
• What activities affect the quality and availability of water for human use?

  • Nitrate conversion to nitrites by bacteria
  • Fossil fuel production
  • Fracking (hydraulic fracturing)
  • Coal ash disposal
  • Sewage and wastewater management
  • Pharmaceutical contamination
  • Urbanization and agriculture
  • Salt erosion from rocks and minerals
• What can nitrates be converted to by bacteria and enzymes?

  Nitrites
• What is nitric oxide's role in the body?

  It is helpful for the body
• What are nitrosamines and their impact?

  They are damaging
• What health risks are associated with nitrites?

  They are implicated in the risk of some cancers, like esophageal, stomach, and colorectal cancers
• How does fossil fuel production affect drinking water?

  It puts considerable strain on drinking water and pollutes groundwater
• What is fracking?

  A process using high pressure, sand, and chemicals to break open subsurface shale to liberate natural gas
• What are the environmental concerns associated with coal ash?

  It contains arsenic and mercury and can leach into groundwater
• How does mountaintop removal affect drinking water?

  It can degrade the drinking water of communities
• What is sewage?

  Wastewater that often contains feces, urine, and laundry waste