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Is Matter Around Us Pure — Science STD 9 — Question

CBSE BoardEnglish MediumSTD 9ScienceIs Matter Around Us Pure3 Marks
Question
Explain why particles of a colloidal solution do not settle down when left undisturbed, while in the case of a suspension they do.
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Answer

In a suspension, the size of the particles is relatively larger than that in a colloidal solution. Also, the molecular interaction in a suspension is not strong enough to keep the particles suspended. Hence the particles settle down when the suspension is left undisturbed for some time. On the other hand, the molecular interaction in a colloidal solution (like milk) is strong enough and does not allow the particles to settle down.

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