Using Resources

• ceramics


  non-metal solids with high melting points that aren't made from carbon-based compounds
• what else can ceramics be made from?

  clay
• clay


  soft material dug up from the ground which can be moulded into different shapes. When it s under high temps it hardens to from ceramic clay
• uses of clay


  Pottery and bricks
• what is glass?


  A ceramic that is generally transparent and can be moulded when hot and can be brittle when thin
• what is most glass made of?

  soda lime glass which is made by heating a mixture of limestone sand and sodium carbonate until it melts
• Borosilicate glass


  has a higher melting point than soda lime glass its made in a similar way to soda lime glass using a mixture of sand and boron trioxide
• composites


  Made of one material embedded in another
• examples of composites


  fibreglass, carbon fibre, concrete, wood
• fibreglass


  consists of fibres of glass embedded in a matrix made of polymer. It has a low density but is very strong.Its used for skis, boats and surfboards
• carbon fibre


  have a polymer matrix the reinforcement is either made of long chains of carbon atoms bonded together or from carbon nanotubes which make them very strong and light so are used in aerospace and sports cars
• concrete


  made from aggregate embedded in cement, its very strong makes it ideal for building materials
• wood


  Natural composite of cellulose fibres held together by an organic polymer matrix
• what two things influence a polymer?

  how its made and what its made from
• what determines the type of bond formed between polymers?

  monomers
• themosoftening polymers


  contain individual polymer chains entwined together with weak forces between the chains. Can be melted and remoulded
• Thermosetting polymers


  Contain monomers that can form cross-links between the polymer chains, holding the chains together in a solid structure

  Unlike thermosoftening polymers, these polymers don't soften when they're heated

  They're strong, hard & rigid
• properties of ceramics


  insulators of heat and electricity they are also brittle and stiff
• properties of polymers


  insulators of heat and electricity, flexible,can be easily moulded and are used in clothings and electrical items
• what does the properties of composites depend on?

  matrix/binder and reinforcement used to make them so have different uses
• properties of metals


  Malleable, Ductile and Good Conductors of Heat and Electricity,shiny and stiff. They can be used in wires cars and cutlery
• How are alloys made?

  By adding another element to the metal. This disrupts the structure of the metal, making alloys harder than pure metals.
• Examples of alloys used in everyday life

  - bronze= copper + tin

  bronze is harder than copper so its used to make medals, decorative ornaments and statues

  - brass= copper + zinc

  brass is more malleable than bronze and is used in situations where lower friction is required eg: water taps and door fittings

  - gold alloys for jewellery:

  pure gold is very soft so metals are used to Harden and strengthen it. pure gold is 24 carat

  - aluminium alloys used to make aircraft: aluminium has a low density which is an important property for manufacturing aircraft but pure aluminium is too soft so its mixed with other metals to make it stronger
• Corrosion


  where metals react with substances in their environment and are gradually destroyed
• What does iron need to be in contact with to rust?

  oxygen and water
• hydrated iron oxide equation


  iron + oxygen + water-> hydrated iron oxide
• When does corrosion happen?

  when a surface of a material is exposed to air
• What other material apart from iron corrodes?

  aluminium
• Why does iron corrode more than aluminium?

  as the iron oxide that is formed when iron corrodes flakes off which leaves more iron exposed to the air unlike aluminium where the aluminium oxide doesn't flake away and instead protects it from any further reactions
• Experiments to show that both oxygen and water are needed for iron to rust


  -if you put an iron nail in a boiling tube with just water it won't rust

  -if you put an iron nail in a boiling tube with just air it won't rust

  -however if you put an iron nail in a boiling tube with air and water it will rust
• Two ways of preventing rust

  coating the iron with a barrier

  sacrificial method
• ways of coating the iron with a barrier

  painting/coating with plastic

  electroplating

  oiling/greasing
• electroplating


  uses electrolysis to reduce metal ions onto an iron electrode which can be used to coat the iron with a layer of different metal that won't be corroded away
• Sacrificial method


  involves placing a more reactive metal such as zinc or magnesium with the iron so that the water and oxygen can react with the sacrificial metal instead of with the iron
• Natural resources


  form without human input and can include anything that comes from the earth sea or air
• What can natural resources be replaced by?

  synthetic products
• renewable resources reform at

  A similar or faster rate than we use them.
• Finite resources


  aren't formed quickly enough to be considered replaceable they include fossil fuels and nuclear fuels such as uranium and plutonium. They also undergo many man made processes to provide fuels and materials from them.
• What are many modern materials made from?

  raw, finite resources
• What do people have to balance when extracting finite resources?

  social, economic and environmental effects of extracting