CLASS 9 NCERT SCIENCE SHORT NOTES IN ENGLISH

Substance :-

There is a type of matter which cannot be separated into other types of matter by physical processes. A pure substance is made up of particles of the same type.

Mixture :-

A mixture is a substance made up of two or more elements or compounds (without being chemically combined). Example :- Air

Types of mixture :- There are two types of mixtures. Homogeneous Mixtures Heterogeneous Mixtures

Homogeneous mixture :-

Those mixtures in which the substances are completely mixed with each other and are indistinguishable from each other, are called homogeneous mixtures. The entire mass has the same composition.

Example :- The solution of sugar and sugar in water is a homogeneous mixture.

Heterogeneous mixture :-

Those mixtures in which substances remain separate and one substance remains spread everywhere in the other substance in the form of small particles, small drops or bubbles, are called heterogeneous mixtures.

In a heterogeneous mixture, its entire mass does not have the same composition.

Example :-

The mixture of sugar and sand is a heterogeneous mixture because different parts of this mixture will have different composition of sugar and sand. Suspension of solids in liquids is also a heterogeneous mixture.

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