Class 6 Science Chapter 5 Separation of Substances, Mixture, Methods of Separation (For CBSE, ICSE, IAS, NET, NRA 2022)

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Separation of Substances

Mixture

  • Mixing two or more substances together is called mixture.
  • In other words, one can say that a mixture consists of a substance composed of two or more substances.
  • Mixtures can be Homogeneous and Heterogeneous.
  • Separation of substances from a mixture is important as the mixture may contain unnecessary or harmful things.
  • For example, a strainer is used for separating tea leaves from the liquid while preparing tea.
  • Using hand, we separate stone pieces from wheat, rice, or pulses.

Homogeneous Mixture

  • The composition is uniform throughout the mixture.
  • This mixture contains two or more ingredients or phases.
  • Different phases mix together, but are physically separate.
  • The phases might be at least:
    • Two solids, liquids, or gases.
    • A solid/liquid (suspension) .
    • Liquid/liquid (emulsion) .
    • Gas/liquid (aerosol) .
    • Gas/solid (smoke) .
  • Some of the examples are blood, soapy water, a mixture of alcohol and water, etc.

Heterogeneous Mixture

  • A mixture in which the composition is not uniform throughout.
  • Phase is a separate layer in a heterogeneous mixture.
  • Some of the examples are Cereal in milk, Orange juice with pulp, Oil, and water, etc.

Various Methods of Separation of Substance

Various Methods of Separation of Substance

Handpicking

  • When the unwanted or unnecessary material is present in a small quantity this process is useful.
  • Using this method, insects or small stones can be separated from wheat and pulses.

Threshing

  • It is the process of separating the edible part i.e.. , grain seeds from the stalk.
  • This can be done using machines, bullocks or sometimes by beating them.

Winnowing

  • Wind is used for separating lighter particles from heavier particles.
  • Grains from husk can be separated using this process.
Winnowing Process of Separation

Sieving

  • This process is used when the size of the substance to be separated is too small to be picked by hand.
  • In this process the bigger particles are retained by the sieve whereas the smaller ones pass through it.
  • It is a very simple, convenient, and time-saving process.
  • Example separating sand from gravel.
Sieving Process

Combine Harvester

  • Machines used in modern day farming.
  • It is a versatile machine designed to efficiently harvest a variety of grain crops.
  • It is in fact a specific type of tractor used for harvesting.
Combine Harvester

Developed by: