summary

• What is the final topic discussed in the material?

  Resources and sustainability
• Why do we need resources like warmth, shelter, food, and transport?

  They are essential for human survival
• What does sustainability mean in resource use?

  Meeting current needs without compromising future generations
• What is potable water?

  Water safe for drinking
• How is freshwater typically sourced in most countries?

  From freshwater sources with low salt levels
• What process is used to sterilize water?

  Chlorination, ozone, or UV light
• What is desalination?

  Removing salt from seawater
• What are two methods of desalination mentioned?

  Distillation and reverse osmosis
• Why is pure or distilled water dangerous to drink in large amounts?

  It can cause cells to become turgid
• What creates wastewater?

  Toilet use and industrial processes
• What is required before wastewater is released back into the environment?

  Treatment to remove harmful substances
• What is sludge in wastewater treatment?

  The solid material that sinks to the bottom
• How is sludge treated?

  Through anaerobic digestion
• What is the liquid effluent from wastewater treatment?

  The liquid that requires aerobic treatment
• How are most metals obtained from their ores?

  By electrolysis or displacement reactions
• What is phyto mining?

  Using plants to absorb minerals from soil
• What is bioleaching?

  Using bacteria to extract metal compounds
• What is an LCA (life cycle assessment)?

  A process to assess environmental impact
• What stages are considered in an LCA?

  Extraction, manufacturing, use, disposal, transportation
• How can we reduce our environmental impact?

  By reducing product use and recycling materials
• Which materials can be recycled infinitely?

  Glass and metal
• What is corrosion?

  Destruction of materials by chemical reactions
• What is rust?

  Corrosion of iron and steel
• What is galvanizing?

  Coating metal with a more reactive metal
• What is bronze an alloy of?

  Copper and tin
• Why is gold jewelry not usually pure gold?

  Pure gold is too soft for jewelry
• What is steel an alloy of?

  Iron and carbon
• What makes stainless steel more resistant to corrosion?

  Presence of chromium or nickel
• Why are alloys usually stronger than pure metals?

  Different sized atoms disrupt the lattice structure
• What is soda-lime glass made from?

  Sand, sodium carbonate, and limestone
• What is borosilicate glass known for?

  Higher melting point than soda-lime glass
• What are ceramics made from?

  Clay heated in a furnace
• What are composites?

  Materials made from two different materials
• What do HDPE and LDPE stand for?

  High density and low density polyethylene
• What is the difference between thermosoftening and thermosetting polymers?

  Thermosoftening melts; thermosetting does not
• What is the Haber process used for?

  To make ammonia for fertilizers
• What gases are used in the Haber process?

  Nitrogen and hydrogen
• What temperature and pressure are used in the Haber process?

  450°C and 200 atmospheres
• Why is 450°C a compromise in the Haber process?

  Balances yield and rate of reaction
• What are NPK fertilizers?

  Fertilizers containing nitrogen, phosphorus, potassium