Is Matter Around Us Pure?

What you will learn

• A mixture contains more than one substance (element and/or compound) mixed in any proportion.

• Mixtures can be separated into pure substances using appropriate separation techniques.

• A solution is a homogeneous mixture of two or more substances. The major component of a solution is called the solvent, and the minor, the solute.

• The concentration of a solution is the amount of solute present per unit volume or per unit mass of the solution.

• Materials that are insoluble in a solvent and have particles that are visible to naked eyes, form a suspension. A suspension is a heterogeneous mixture.

• Colloids are heterogeneous mixtures in which the particle size is too small to be seen with the naked eye, but is big enough to scatter light. Colloids are useful in industry and daily life. The particles are called the dispersed phase and the medium in which they are distributed is called the dispersion medium.

• Pure substances can be elements or compounds. An element is a form of matter that cannot be broken down by chemical reactions into simpler substances. A compound is a substance composed of two or more different types of elements, chemically combined in a fixed proportion.

• Properties of a compound are different from its constituent elements, whereas a mixture shows the properties of its constituting elements or compounds.