Given below is a comparison of two types of changes:

Comparison of properties of a true solution, colloidal solution, and suspension

Test of a colloidal solution or a suspension.
(i) A colloidal solution is turbid and particle settles down on adding a salt. In a suspension, particles settle down on keeping under the influences of gravity.
(ii) If the particles in a heterogeneous and opaque solution can be seen with naked eyes and get settled on keeping, then it is a suspension.
(b) (i) decrease of temperature
(ii) Increase of temperature.

Comparison of properties of true solution, colloidal solution, and suspension

Test of a colloidal solution or a suspension.
(i) A colloidal solution is turbid and the particle settles down on adding salt. In a suspension, particles settle down on keeping under the influences of gravity.
(ii) If the particles in a heterogeneous and opaque solution can be seen with naked eyes and get settled on keeping, then it is a suspension.

Homogeneous mixtures
(a) Solid solution. Alloys, e.g., brass, steel, bronze.
(b) liquid solution. Sugar solution in water, seawater, alcohol in water.
(c) Gaseous solution. Air, natural gas.
Heterogeneous mixtures
(a) Solid + Solid Sugar and sand, iron filings and sulphur, copper sulphate and potassium permanganate
(b) Solid +  Liquid Pastes, suspensions, etc.
(c) Solid + gas Smok
(d) Liquid + Liquid Milk, emulsions.
(e) liquid + Gas Soap bubbles.

Chromatography is the technique whereby different soluble components of a mixture are separated due to their differential movement over a stationary phase under the influences of the mobile phase, i.e., solvent. If water is the solvent then the component that is more soluble in water will move faster. In this way, different components get separated
The technique of chromatography is used to separate
(a) Components of dyes
(b) Pigments from natural colours.
(c) Amino acids.

The solubility of potassium nitrate is 62 g at 313 K. it means it is the max. amount soluble at 313 K in 100 g of solution.
Amount of salt = 62 g
Amount of water = 100 - 62 = 38 g
Amount of KNO₃ in 50 g water = \({62\over38}\times {50\over1}={81.58 g}\)
The solubility of a salt increase with rise in temperature.

(i) True Solution. A true solution is defined as a homogeneous mixture of two or more substances. The term homogeneous means that every portion of the solution has the same properties, e.g., sugar dissolved in water, iodine in ethyl alcohol (tincture).
(ii) Solute. The substance(s) present in smaller proportions in a solution is called the solute.
(iii) Solvent. The substance present in a larger in large proportion in a solution is called the solvent. If a homogeneous mixture or a solution is formed by dissolving 2 g salt in 100 g water, then salt is the solute and water is the solvent.
(iv) Solubility. The maximum amount of the solid that can be dissolved in a given amount of the solvent (water) is termed its solubility at that temperature.

Mass of silver (Ag) ornament = mg
Mass of gold used for polishing = \(\frac{1}{100}\times\) mg = 0.01 mg
Atomic mass of Ag = 108 u
\(\therefore\) 1 mole of Ag = 108 g = 6.022 x 10²³ atoms
Thus, 108 g of Ag have atoms = 6.022 x 10²³
\(\therefore\) mg of Ag have atoms = \(\frac{6.022\times 10^{23}}{108}\)
Similarly, atomic mass of gold (Au) = 197 u
1 mole of Au = 197 g = 6.022 x 10²³ atoms
Thus, 197 g of Au have atoms = 6.022 x 10²³
\(\therefore\) 0.01 mg of Au will have atoms = \(\frac{6.022\times 10^{23}\times 0.01\ m}{197}\)
\(\therefore\) Ratio of the number of atoms of gold and silver = \(\frac{6.022\times 10^{23}}{197}\times 0.01\ m; \frac{6.022\times 10^{23}}{108}m\)
= \(\frac{1}{19700}:\frac{1}{108}\) 
= 108: 19700