Materials

• What is a ceramic material?

  Ceramic materials are compounds.
• What are the main physical properties of ceramics?

  • hard
  • brittle
  • stiff
  • solid at room temperature
  • electrical insulators
• What are the main chemical properties of ceramics?

  They are unreactive with water, acids or alkali
• List 3 uses of ceramics:

  • building bricks
  • plates
  • jet engine blades
• Explain why ceramics have high melting points

  They have strong forces between the atoms. A lot of energy is required to break these forces.
• What is a polymer?

  a substance with very long molecules made from repeating units of smaller molecules
• Two types of polymers:

  • synthetic
  • natural
• 3 examples of natural polymers:

  • wool
  • rubber
  • cotton
• 2 examples of synthetic polymers:

  • poly(ethene)
  • poly(vinyl chloride)
• Describe the difference between low density poly(ethene) and high density poly(ethene)

  Low density poly(ethene) molecules are less particles per$cm^3$ squared where as high density poly(ethene) have more particles per$cm^3$
• Describe the similarities between low density poly(ethene) and high density poly(ethene)

  Both are strong and flexible
• What is a composite material?

  mixture of materials
• Name two materials in carbon-fibre-reinforced plastic

  • carbon fibres
  • polymers
• What are the main properties of carbon-fibre-reinforced plastic?

  • low density
  • rust proof
  • strong
  • malleable
• What are the disadvantages of carbon-fibre-reinforced plastics?

  very expensive
• Name two materials in glass-fibre-reinforced aluminium

  • aluminium
  • glass fibre