For example, salt is a pure substance made only of sodium chloride ... It still contains some impurities, such as dissolved oxygen, carbon dioxide, minerals and microorganisms.

Explanation: A pure substance is one which is made up of only ... A mixture of sulphur and carbon disulphide is heterogeneous and shows Tyndall effect because in a colloidal solution the particles ...

For example, salt is a pure substance made only of sodium chloride ... It still contains some impurities, such as dissolved oxygen, carbon dioxide, minerals and microorganisms.