Materials

• Pure Substances


  • Elements are made up of just one type of atom. Ex. Gold, oxygen, sodium, iron
  • Compounds are made up of more than one type of atom. Ex. CO2, H2O, Ammonia
• Pure Substances


  • The Physical properties of pure substance such as melting point, boiling point and conductivity cannot be altered
• Homogenous mixtures


  Can't be easily separated and are hard to distinguish one part from another
• Metals


  • Make up 80% of all known elements, account for about 50% of the Earth's mass
  • Are valuable due to useful properties such as tensile strength, malleability, ductility, conductivity and high melting and boiling points
• Alloy


  A mixture of one metal with other metals or small amounts of non-metals to make the metal more suitable for a particular task. Ex. Steel, brass, bronze, solder
• Polymers


  • Materials with molecular structure composed of many repeating smaller units bonded together
  • Characterised by covalent bonds (non-metals)
  • "poly" meaning many and "mer" meaning parts in Greek. Ex polyethene, nylon, rubber and latex
• Polymers


  • Can exhibit vastly different physical properties especially which often contract that of metals including low density, corrosion resistance and electrical resistance
• Ceramics


  Inorganic, non-metallic solids which contain metal and non-metal elements held together by ionic and covalent bonds
• Ceramics


  • The vast range of chemical compositions in Ceramics allows for a wide range of properties which often include compressive strength and insulation
• Composite materials


  The combination of two or more distinct materials with different physical and chemical properties. For example reinforced concrete has the tensile strength of steel and the compressive strength of the concrete
• Nanotechnology


  • The branch of science that investigates the design, properties and applications of materials produced on this scale
  • A nanometre is one-billionth of a meter 10-9m
  • Nanoscale refers to things that are between 1-100 Nanometres
• The study and development of these materials has only been made possible by electron microscopes and scanning tunnel microscopes
• Raw materials


  Mixtures which contain a combination of substances which often need to be purified
• Separation techniques


  • Particle size such as a sieve
  • Density such as sedimentation, decantation and centrifuge
  • Boiling Point such as evaporation and distillation
  • Electric charge such electrostatic separation and chromatography
• Distillation


  A common separation technique