4th Sep '25

Schemes of Work

C2
- C2.6
  - Lesson 01 - How can corrosion be useful? Lesson Plan Lesson Title
    - Corrosion is the destruction of materials by chemical reactions with substances in the environment.
    - Corrosion can be prevented by applying a coating that acts as a barrier, such as greasing, painting or electroplating.
      - Suggested Activity:
        Practical investigation placing nails in test tubes that contain water, oil, air or smeared with Vaseline.
        Get technitians to keep for a week and ask for them back to evaluate
        GF: Why are sacrifical metals used in boats?
        Equipment Required:
        Nails
        Test tubes
        Rubber bungs
        oil
        Vaseline
    - Students should be able to describe experiments and interpret results to show that both air and water are necessary for rusting.
    - Rusting is an example of corrosion. Both air and water are necessary for iron to rust.
    - Some coatings are reactive and contain a more reactive metal to provide sacrificial protection, eg zinc is used to galvanise iron.
    - Aluminium has an oxide coating that protects the metal from further corrosion.
    - Students should be able to explain sacrificial protection in terms of relative reactivity.
  - Lesson 02 - How are alloys made? Lesson Plan Lesson Title
    - Most metals in everyday use are alloys.
      - Suggested Activity:
        Match up alloys names and what they are made from.
        Practical: making solder
        Equipment Required:
        Each group will need:
        Lead (TOXIC, DANGEROUS FOR THE ENVIRONMENT), about 2 g
        Tin, about 2 g
        Carbon powder, about 2 g
        
        Eye protection
        
        Thermal protection gloves
        
        Each working group requires:
        Crucible
        Pipe clay triangle
        Bunsen burner
        Tripod
        Heat resistant mat
        Spatula
        Tongs (Note 1)
        Casting sand (Note 2)
        Metal sand trays or sturdy metal lids, 2 (Note 2)
        Balance (no decimal places needed)
    - Bronze is an alloy of copper and tin. Brass is an alloy of copper and zinc.
    - Gold used as jewellery is usually an alloy with silver, copper and zinc. The proportion of gold in the alloy is measured in carats. 24 carat being 100 % (pure gold), and 18 carat being 75 % gold.
    - Steels are alloys of iron that contain specific amounts of carbon and other metals.
    - High carbon steel is strong but brittle. Low carbon steel is softer and more easily shaped.
    - Steels containing chromium and nickel (stainless steels) are hard and resistant to corrosion.
    - Aluminium alloys are low density.
    - Students should be able to recall a use of each of the alloys specified.
  - Lesson 03 - What products can be made from the Earth's materials? Lesson Plan Lesson Title
    - Most of the glass we use is soda-lime glass, made by heating a mixture of sand, sodium carbonate and limestone.
      - Suggested Activity:
        Making concrete - testing strength using masses (consider making lesson before or testing in subsequent lessons)
        Equipment Required:
        making concrete:
        sand
        gravel
        water
        moulds
    - Borosilicate glass, made from sand and boron trioxide, melts at higher temperatures than soda-lime glass.
    - Students should be able to, given appropriate information compare quantitatively the physical properties of glass and clay ceramics, polymers, composites and metals.
    - Students should be able to interpret and evaluate the composition and uses of alloys other
      than those specified given appropriate information.
    - Clay ceramics, including pottery and bricks, are made by shaping wet clay and then heating in a furnace.
    - Most composites are made of two materials, a matrix or binder surrounding and binding together fibres or fragments of the other material, which is called the reinforcement.
    - Students should be able to recall some examples of composites.
  - Lesson 04 - Why are some plastics hard and others flexible? Lesson Plan Lesson Title
    - Students should be able to, given appropriate information explain how the properties of materials are related to their uses and select appropriate materials.
    - The properties of polymers depend on what monomers they are made from and the conditions under which they are made. For example, low density (LD) and high density (HD) poly(ethene) are produced from ethene.
      - Suggested Activity:
        Observe everyday examples of LH and HD polymers to deduce their properties and structure
        Equipment Required:
        cleaned out examples of high and low density plastics, as below or similar:
        
        Low density:
        milk carton
        food packaging
        clingfilm
        carrier bags
        plastic fizzy drink bottle
        
        high density:
        hard plastics (trays)
        pens
        drink bottle
    - Thermosoftening polymers melt when they are heated. Thermosetting polymers do not melt when they are heated.
    - Students should be able to explain how low density and high density poly(ethene) are both produced from ethene.
    - Students should be able to explain the difference between thermosoftening and thermosetting polymers in terms of their structures.