Science Curiosity Notes Class 6 English Medium 2026-27

Science Curiosity Chapter 9. Methods of Separation in Everyday Life

CBSE Notes New Syllabus: Class 6

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Chapter 9. Methods of Separation in Everyday Life

We often need to separate useful substances from unwanted materials in our daily life. Different methods of separation are used depending on the properties of the substances present in a mixture.

CBSE Notes – Key Points

Mixture

Mixture: A mixture is a physical combination of two or more substances.

Examples of Mixtures

(i) Sand and salt

(ii) Rice and stones

(iii) Tea with tea leaves

(iv) Oil and water

Characteristics of a Mixture

(i) Contains two or more substances.

(ii) Components can be separated by physical methods.

(iii) Each substance keeps its own properties.

Methods of Separation

Methods of Separation: Different techniques used to separate the components of a mixture.

Common Methods

(i) Handpicking

(ii) Threshing

(iii) Winnowing

(iv) Sieving

(v) Sedimentation

(vi) Decantation

(vii) Filtration

(viii) Evaporation

(ix) Churning

(x) Magnetic Separation

Handpicking

Handpicking: Handpicking is the method of removing large visible impurities by hand.

Examples

(i) Removing stones from rice.

(ii) Removing spoiled grains from pulses.

Key Points

(i) Suitable for small quantities.

(ii) Used when impurities are clearly visible.

Threshing

Threshing: Threshing is the process of separating grains from harvested stalks.

Examples

(i) Separating wheat grains.

(ii) Separating rice grains.

Key Points

(i) Done manually or by machines.

(ii) Commonly used after harvesting crops.

Winnowing

Winnowing: Winnowing is the process of separating lighter particles from heavier particles using wind.

Examples

(i) Separating husk from grains.

Key Points

(i) Requires moving air.

(ii) Lighter particles are blown away.

Sieving

Sieving: Sieving is the process of separating particles of different sizes using a sieve.

Examples

(i) Separating bran from flour.

(ii) Separating sand from gravel.

Key Points

(i) Used when particles differ in size.

(ii) Fine particles pass through the sieve.

Sedimentation

Sedimentation: Sedimentation is the process in which heavier insoluble particles settle at the bottom of a liquid.

Examples

(i) Mud settles at the bottom of water.

(ii) Sand settles in muddy water.

Key Points

(i) Used for insoluble substances.

(ii) Heavier particles settle due to gravity.

Decantation

Decantation: Decantation is the process of carefully pouring the clear liquid into another container.

Examples

(i) Separating clear water from muddy water.

(ii) Separating oil from water.

Key Points

(i) Done after sedimentation.

(ii) The settled particles remain at the bottom.

Filtration

Filtration: Filtration is the process of separating insoluble solids from liquids using a filter.

Examples

(i) Separating tea leaves from tea.

(ii) Filtering muddy water.

Key Points

(i) Filter paper traps the solid particles.

(ii) The clear liquid passes through the filter.

Evaporation

Evaporation: Evaporation is the process of obtaining dissolved solids by heating a solution.

Examples

(i) Obtaining salt from seawater.

(ii) Drying wet clothes.

Key Points

(i) The liquid changes into vapour.

(ii) The dissolved solid remains behind.

Churning

Churning: Churning is the process of separating butter or cream from curd.

Examples

(i) Butter from curd.

(ii) Cream from milk.

Key Points

(i) Done using a churner or mixer.

(ii) Butter floats on the surface.

Magnetic Separation

Magnetic Separation: Magnetic separation is the process of separating magnetic materials using a magnet.

Examples

(i) Iron filings from sand.

(ii) Iron nails from waste materials.

Key Points

(i) Works only for magnetic substances.

(ii) Iron, nickel, and cobalt are magnetic materials.

Selection of Separation Method

Selection of Separation Method: The method of separation depends on the physical properties of the substances.

Applications in Daily Life

Applications: Methods of separation are used in many activities at home, in agriculture, and in industries.

Examples

(i) Cleaning rice and pulses before cooking.

(ii) Separating tea leaves from tea.

(iii) Obtaining salt from seawater.

(iv) Sieving flour before cooking.

(v) Separating butter from curd.

(vi) Purifying drinking water.

(vii) Removing iron pieces from scrap.

(viii) Separating grains after harvesting.

Scientific Terms

Scientific Terms: These terms are important for understanding methods of separation.

Quick Revision

(i) A mixture contains two or more substances.

(ii) Different mixtures require different separation methods.

(iii) Handpicking removes large visible impurities.

(iv) Threshing separates grains from stalks.

(v) Winnowing separates lighter husk from heavier grains.

(vi) Sieving separates particles of different sizes.

(vii) Sedimentation settles heavy insoluble particles.

(viii) Decantation separates the clear liquid.

(ix) Filtration removes insoluble solids from liquids.

(x) Evaporation is used to obtain dissolved solids.

(xi) Churning separates butter from curd.

(xii) Magnetic separation removes magnetic substances.

Keywords

Mixture: A physical combination of two or more substances.

Handpicking: Removing visible impurities by hand.

Threshing: Separating grains from harvested stalks.

Winnowing: Separating lighter and heavier particles using wind.

Sieving: Separating particles of different sizes.

Sedimentation: Settling of heavier insoluble particles.

Decantation: Pouring the clear liquid carefully.

Filtration: Separating insoluble solids using a filter.

Evaporation: Obtaining dissolved solids by removing the liquid.

Churning: Separating butter from curd.

Magnetic Separation: Separating magnetic materials using a magnet.