Activity 2.5 NCERT Class 9 Science Is Matter Around Us Pure

Activity 2.5 NCERT Class 9 Science Chapter 1 Is Matter Around Us Pure

Brief procedure:

Activity 2.5 asks us to separate cream from the milk by centrifugation.


Centrifugation of the milk separates them into skimmed milk and cream at the top.

Activity 2.5 NCERT Class 9 Science
A woman churning milk to get butter, pic from 1893.

Components of a mixture may have different densities. When such a mixture is shaken vigorously, lighter particle separates from the rest and float on the surface.  Milk fats are lighter than the rest of the mixture. As a result when we shake milk vigorously milk fat separate and start floating on the surface.

Inference /conclusion:

We can separate components of a mixture by centrifugation if the components of the mixture have different densities.


Separation of components from the blood in pathological testing.

Preparation of butter from the milk.

Next: Separation of immiscible liquid, class 9 Science activity 2.6.

See also: Experiment to demonstrate the separation of a mixture by evaporation, Activity 2.4.

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