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Subject :NSO    Class : Class 4

Kavita puts some sand into a beaker filled with water and stirs it. She has to separate water from the mixture of sand and water. What should she do?

(A) Evaporation followed by sedimentation

(B) Filteration followed by evaporation

(C) Sedimentation followed by decantation

(D) Decantation followed by filteration
Hello,I need the reasoning for all the options.

Ans 1:

Class : Class 5
(A) cannot be the right answer as once the water vaporizes, there is no scope for sedimentation. (B) cannot be the right answer as once the mixture is filtered, the sand shall be collected on the filter paper while the clean water shall be collected in a beaker.Evaporation is not required. The answer is (C) because sand is heavier than water and shall settle down at the bottom of the beaker.This process is called sedimentation.Subsequently,the clear water from the top can be decanted out. (D) cannot be the right answer as once decantation is done, the clear filtrate shall be left over and filtration is not required.

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