INTRODUCTION / DEFINITIONS.
A pure substance is a single substance or matter which cannot be separated into other kinds of matter by any physical process
A change which can be easily reversed is a physical change while the one which cannot be reversed is a chemical change in nature
A solution becomes saturated if the solute starts separating at the bottom of the container in which the solution is being prepared at a given temperature. A saturated solution generally becomes unsaturated upon heating.
Colloidal solutions are also heterogeneous in nature like suspensions, but they have smaller size of the particles which are distributed. It ranges between 1 nm to 100 nm i.e., in between the particle size of true solution and suspension.
A suspension is a heterogeneous mixture in which the solid particles are spread throughout the liquid without dissolving in it. They settle as precipitate if the suspension is left undisturbed for sometime.
A solution or homogeneous mixture is the mixture of two or more non-reacting substances
Mixtures can be homogeneous only if the constituents present are uniformly mixed and there is no boundary of separation of these constituents.
A mixture is said to be heterogeneous if it does not have a uniform composition and also has visible boundaries of separation between the constituents.
A saturated solution can be made unsaturated in two ways :
By increasing the temperature or by heating and by adding more of the solvent or by diluting the solution.
Silicon (Si) is a metalloid.
Metals are malleable and ductile, i.e. they can be beaten into sheets and drawn into wires.
Water helps in separating ions from a salt. This inter-ionic forces decreases and the ions gets dispersed.Nitrogen is one of the constituents of air. It can be separated with the help of fractional distillation.
Chromatography helps in separating dye from blue ink.
Centrifugation or churning helps in separating cream from milk.
Ammonium chloride is of volatile nature while common salt (sodium chloride) is not. The separation can be done with the help of sublimation.
A solution is said to be saturated if no more of a solute can dissolve in it at a given temperature.
In a colloidal solution,these particles scatter the light rays as they fall on them. Because of scattering, the path of the light as well as the particles become visible. But in a true solution, the particle size is so small (less than 1 nm) that these particles are not in a position to scatter the light.