Specification Point 9.38C:
  • Compare, using data, the physical properties of glass and clay ceramics, polymers, composites and metals

Glass Ceramics

  • Usually made by heating limestone, sand and sodium carbonate.
  • Transparent and strong but brittle, especially when in thin sheets.
  • Can be moulded into shapes.
  • Poor conductor of heat and electricity.

Clay Ceramics

  • Usually made from decomposed rock.
  • Opaque, soft and malleable when extracted from the ground.
  • Hardened when heated to high temperatures, becomes brittle after heating.
  • Poor conductor of heat and electricity.


  • Can be tailor designed to have specific properties for specific uses.
  • Can be made opaque or transparent.
  • Usually tough and flexible, some specialist polymers can be brittle.
  • Poor conductor of heat and electricity.


  • Made from two components: reinforcement and matrix.
  • The matrix is what binds the reinforcement together.
  • Common examples include fibreglass and steel reinforced concrete.

Composite physical properties table, Edexecl GCSE Chemistry
Carbon Fibre, Edexcel GCSE Chemistry

Diagram showing the structure of carbon fibre composite


  • Shiny, malleable and ductile so can be hammered into different shapes.
  • Can be mixed with other elements to form alloys, which have different properties to the elements they contain.
  • Corrosion resistant metals can be produced which last longer than other metals.
  • Good conductors of heat and electricity.

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Morgan Curtin Chemistry

Author: Morgan

Morgan’s passion for the Periodic Table begun on his 10th birthday when he received his first Chemistry set. After studying the subject at university he went on to become a fully fledged Chemistry teacher, and now works in an international school in Madrid! In his spare time he helps create our fantastic resources to help you ace your exams.