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• Mixture: Combination of different substances in which no chemical reaction takes place
• Need of separation:
  • Sewage water from homes can be cleaned from dust, microbes, etc, which can be reused for other purposes
  • Before cooking it is necessary to remove stones from food grains
  • Industrial waste contains impurities which are needed to be removed before letting into reservoirs
  • To extract iron from iron ore
  • To extract petrol, diesel, kerosene etc from crude oil
• Handpicking – Picking desired materials with hands. E.g. removing pieces of dust husk, stones from foodgrains
• Threshing – Used to separate food grain and husk from plant body. E.g. to separate husk, part in which husk is located is beaten with stick or animal are allowed to walk on the body
• Winnowing – after threshing food grains remains mixed with husk, to remove this husk winnowing is used. Winnowing is useful when one particle is lighter than the other. With the flow of wind lighter particles to be removed gets carried away with wind.
• Sieving – sieves are used when one want to separate particles of different sizes. While seiving bigger particles remains in the mesh while smaller particles moves out through it. E,g, separation of fine sand from pebbals during construction
• Sedimentation and decantation –
  • Sedimentation – The process of settling of heavier components at the bottom of water is called sedimentation.
  • Decantation – The method of separation which is based on ability of components to float or sink in water is called decantation
• Filtration – Process of filtering solid from liquid is called filtration. E.g. separation of mud from water
• Evaporation and condensation –
  • Evaporation – Process of conversion of water into its vapour
  • Condensation – Process of conversion of vapour into water
  • Boiling point – temperature at which the liquid substance get converted into vapour form
  • Evaporation and condensation is helpful in extracting petrol, diesel, kerosene etc from crude oil
• Solubility in water
  • Solvent – material that dissolves a substance in it
  • Solute – substance that is dissolved in solvent
  • Solution = solute + solvent
  • Saturated solution – solution in which we can not dissolve more amount of solute