Using Resources

• Ceramics are a group of hard, brittle, heat-resistant, and corrosion-resistant materials.
• Two main groups of ceramics are clay ceramics and glass.
• Most of the glass we use is soda-lime glass. This is made by melting a mixture of sand (silicon oxide), sodium carbonate, and limestone, then allowing the molten liquid to cool and solidify.
• Borosilicate glass is made by heating sand with boron trioxide. Borosilicate glass has a much higher melting point than soda-lime glass.
• A composite material consists of two or more materials with different properties, that have been combined to produce a material with more desirable properties
• Composite materials are made from two components:

  1. The reinforcement - long solid fibres or fragments
  2. The matrix - binds the reinforcement together. Usually something that starts soft and hardens
• Generally, polymers are flexible, easily shaped, and good insulators of heat and electricity.
• LDPE - low density poly(ethene)

  • Conditions: Moderate temperatures, high pressures, catalyst
  • Properties: More flexible but weaker
  • Uses: Carrier bags
• HDPE - high density poly(ethene)

  • Conditions: Low temperature / pressure, catalyst
  • Properties: More rigid but stronger
  • Uses: Drainpipes
• Thermosoftening polymers are made from lots of polymer chains, held together by weak intermolecular forces. These break easily when heated, causing the polymer to melt. It can then be remoulded into a different shape and will harden again when cooled.
• Thermosetting polymers are made from lots of polymer chains, held together by strong covalent bonds. These require lots of energy to break, so don’t soften when heated. These polymers are hard, strong and rigid.
• Corrosion - metals are slowly broken down by reacting with substances in their environment
• Rusting:

  Iron + oxygen + water ➔ hydrated iron (III) oxide
• Aluminium doesn't break down as it corrodes, as aluminium oxide forms a protective layer, preventing further oxidation
• Barrier methods to prevent iron rusting:

  • Painting the iron
  • Oiling or greasing it
  • Electroplating (using electrolysis to cover the metal in another metal)
• What is galvanisation?


  Coating metal in a thin layer of zinc. Sacrificial method.
• A life cycle assessment (LCA) assesses the environmental impacts of products.
• Limitations of life cycle assessments (LCAs)


  • Companies can manipulate their LCAs to look more favourable
  • Comparing different harms is difficult
  • Gathering all of the required data about each step is difficult
• Name the acid used to make ammonium nitrate fertiliser

  nitric acid
• In thermosetting polymers, the bonds between chains are called cross-links.
• Iron is used as a catalyst in the Haber Process
• Desalination is the removal of salt from water to make it potable.