Science Class 6 Notes Chapter 9 Curiosity

Methods of Separation in Everyday Life

Handpicking

• A simple method used to separate substances based on differences in size, color, or shape.
• Example: Removing small stones from grains like rice or wheat.

Threshing

• The process of separating grains from stalks by beating.
• Commonly used by farmers after harvesting crops.

Winnowing

• Separating lighter components like husk from heavier grains by blowing air or using wind.
• Traditionally done using a bamboo tray (soop).

Sieving

• Used to separate components of different sizes.
• Example: Sieving flour to remove bran or small stones.

Evaporation

• A method to separate dissolved solids from liquids by heating.
• Example: Obtaining salt from seawater.

Sedimentation and Decantation

• Sedimentation: The heavier solid settles at the bottom when left undisturbed.
• Decantation: The liquid is gently poured out, leaving the solid behind.
• Example: Separating tea leaves from tea.

Filtration

• Separates insoluble solids from liquids using a filter (e.g., filter paper or cloth).
• Example: Filtering muddy water.

Churning

• Used to separate butter from curd by rotating or shaking.
• Butter, being lighter, floats at the top.

Magnetic Separation

• Separating magnetic materials from a mixture using a magnet.
• Example: Removing iron nails from sawdust.

Summary of Separation Methods

• Handpicking: Removes larger, visible components.
• Threshing: Separates grains from stalks.
• Winnowing: Uses wind to blow away lighter substances.
• Sieving: Separates components based on particle size.
• Evaporation: Recovers solids from a solution.
• Sedimentation & Decantation: Separates heavier particles by settling.
• Filtration: Uses filters to separate solids from liquids.
• Churning: Extracts butter from curd.
• Magnetic Separation: Isolates magnetic materials from non-magnetic ones.