Elements, Compounds and mixtures

•       An element is a substance which can neither be broken nor built from two or more simple substances by any known physical or chemical methods. The elements are building block of matter i.e. any matter is made up of one or more types of elements. Substances built of only one kind of atoms are called elements.
•      Compounds is a pure substance which contains two or more than two elements combined together in some fixed proportion by weight and which can be decomposed into two or more elements by a suitable method. It is always homogeneous.
•           Mixture is a material obtained by mixing two or more than two substance (elements or compounds) in any proportion. In it, the properties of constituents remain unchanged. It may be homogeneous or heterogeneous. 

1.                 Separation of components of the mixture depends upon (i) the physical state of the substance in the mixture (i.e. solid, liquid, gases or solution) (ii) physical properties (i.e. melting point, boiling point, solubility) of each component. The choice of the method used depends on (a) the type of the mixture to be separated. (b) The nature of each component to be separated.
2.               Types of mixtures:  Common types of mixtures are (i) solid – solid mixture (ii) solid – liquid mixture (iii) liquid – liquid mixture (iv) gas – liquid mixture (v) gas – gas mixture (vi) gas – solid mixture.