Materials

• Different types of materials around us

  • Wood
  • Metal
  • Ceramic
  • Rubber
  • Glass
  • Plastic
  • Fabric
• Wood

  • Comes from trees
  • Used to make furniture, musical instruments, sports equipment, paper
• Metal

  • Dug up from the ground
  • Examples: gold, iron, copper, aluminium
  • Used to make jewellery, gates, railings, electrical wires, cooking pots, drink cans, window frames, aeroplanes
• Ceramic

  • Made from clay
  • Used to make vases, bowls, plates, cups, bricks, toilets, man-made teeth
  • Needs to be shaped, dried, and fire-baked in a hot oven to harden
• Rubber

  • Can come from the sap of a rubber tree or be man-made from oil
  • Used to make many objects like gloves, bands, balls, bicycle tyres, raincoats, rain boots
• Rubber was once thought to be a useless material, but Charles Goodyear found a solution to allow it to be used in different kinds of weather
• Glass

  • Made from sand
  • Used to make glass tanks, window panes, light bulbs, spectacles
  • Can be blown into different shapes when hot
• Plastic

  • Made in factories using oil from the ground
  • Used to make bottles, bags, shoes, pens, toothbrushes
  • Usually long-lasting, so needs to be recycled or reused to avoid waste
• Fabric

  • Can come from animals (wool, silk) or plants (cotton)
  • Used to make sweaters, scarves, clothing, bedsheets, shirts, towels
• Objects are made up of various types of materials: wood, metal, ceramic, rubber, glass, plastic and fabric
• Physical properties

  Something that can be measured or observed about a material
• Strength

  • Ability of a material to be pulled or pushed without breaking or tearing
  • Strong materials do not break easily, weak materials break easily
• The physical property of a material can change according to how the material is treated
• Flexibility

  • Ability of a material to bend without breaking
  • Flexible materials bend easily without breaking, rigid materials break when bent
• Flexible materials

  • Rubber tile
• Rigid materials

  • Ceramic tile
• Rubber is the most flexible, metal is the least flexible among rubber, plastic, and metal tubes
• Ability to float or sink in water

  • Some materials sink in water, others float
• Sinking materials

  • Metal block
  • Metal spoon
• Floating materials

  • Wooden block
  • Wooden spoon
• Ships made of metal can float on water because there is a lot of trapped air inside the ship
• Waterproof

  • Materials that do not absorb water at all
• Waterproof materials

  • Rubber
  • Plastic
  • Glass
• Flexibility

  • The most flexible material among the three tubes
• Floating or sinking in water

  When objects are placed in water, some will float, while others will sink
• Material affecting ability to float or sink

  The material of an object affects the ability of the object to float or sink
• Most metals sink in water, while most types of wood float on water
• Ships are made of metals, but they are able to float on water because there is a lot of trapped air inside the ship
• Waterproof

  Materials that do not absorb water at all
• Waterproof materials

  • Rubber
  • Plastic
  • Glass
  • Metals
• Non-waterproof

  Fabric absorbs water and allows water to pass through it
• Fabric can be made waterproof by applying a layer of wax over it
• Transparency

  How much light can pass through a material
• Transparent materials

  • Glass
  • Some plastics
• Translucent materials

  • Frosted glass
  • Some plastics
• Opaque materials

  • Rubber
  • Wood
  • Metal
• Materials have different physical properties: strength, flexibility, the ability to float or sink, waterproof and transparency
• Object

  Things used for different purposes
• Objects

  • Bath towel
  • Scissors
  • Raincoat
  • Water hose
• Materials used for objects

  • Fabric
  • Metal
  • Plastic
  • Rubber