In Ram's method separation of salt from clay particles is not perfect.First, you have to use water again for crystallisation, secondly, crystallisation does not separate salt from clay so easily.Steps followed by Shyam are perfect and all components are separated into pure form.

Take the solvent water, in a kettle. Heat it. When the solvent boils, add the solute, milk. milk and water form a solution. then pour some tea leaves over a sieve. pour a slowly hot solution of milk solution over tea leaves. Colour of tea leaves goes into solution as filtrate. The remaining tea leaves being insoluble remain as residue. Add requisite amount of sugar, a solute to the tea solution which dissolves and the tea is ready.

(a) Non-metals do not conduct heat and electricity but carbon in the form of graphite is a good conductor of electricity.
(b) Non-metals are brittle but carbon in the form of diamond is very shining substances

(i) Silver - elements
(ii) Methane - compound
(iii) Water - compound
(iv) Mecury : Element.

(i) centrifugation or decantation.
(ii) evaporation or distillation or crystallisation.
(iii) Sublimation.
(iv) Chromatography.
(vi) Separating funnel.
(vii) Fractional distillation.
(viii) Cooling and fraction.

(a) By use of separating funnel. 
(b) No. Water and alcohol when mixed from a single layer and thus separating funnel cannot be used to separate alcohol dissolved in water.

The given mixture cannot be a solution because a solution is always homogeneous, if this is left undisturbed for some time and no solid settle down, then it is colloid otherwise it is suspension.

Amount of alcohol in 100 mL solution = 12 mL
Amount of water = 100 - 12 = 88 mL
88 mL water and 12 mL alcohol are to be mixed with to get 12% of alcohol.

Water is a compound because:
(i) The composition of hydrogen and oxygen in water taken from any source is the same.
(ii) The properties of water are different from that of its constituents, i.e., H₂ or O₂.

A pure substance always has the same colour, taste or texture at a given temperature and pressure. Also it has fixed point or boiling point at constant pressure. Also it has a fixed melting point or boiling point at constant pressure. For example, pure water boils at 373k at 1 atmospheric pressure. But water containing some invisible dissolved substance boils at a temperature above 373k.

Mixture	Compounds
1. elements or compounds just mix retaining the properties of a constituent substance	1. Element reacts to form a new substance that has totally different properties.
2. A mixture has a variable composition	2. The composition of the new substance or compound is fixed.
3. The constituent can be separated fairly easily by physical methods.	3. The constituents can be separated only by chemical methods.

metal	Non-metal
1. metals are solids at room temperature.	1. Non-metals may be a gas, a liquid or a solid at room temperature.
2. metals have a shiny metallic lustre. Their shining can be intensified by polishing.	2. Non-metals have a dull non-metallic lustre.
3. metals are hard substances.	3. Non-metals have a hardness of varying category
4. Metals are malleable.	4. non-metals are non-malleable
5. metals are ductile and can be drawn into wires.	5. Non-metals are not ductile and cannot be drawn into wires.
6. metals have high specific gravity.	6. non-metals have low specific gravity.
7. metals are good conductors of heat and electricity.	7. non-metals are bad conductors of electricity, except graphite which is a good conductor of electricity.
8. metals form alloys with other metals.	8. non-metals do not form alloys with other non-metals.

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

Property	True solution	Colloidal solution	Suspension
(1) Appearance	homogeneous and transparent	Heterogeneous and translucent	heterogeneous and opaque
(2) particle size	< 1 nm (10-7 cm)	1 nm - 100 nm	> 100 nm (10-5 cm)
(3) Visibility	particles are not visible even with a powerful microscope	Particles can be seen with a high power microscope	particles can be seen with naked eyes
(4) Stability	Stable	Stable	Unstable
(5) Diffusion	Diffuse rapidly	Diffuse slowly	Do not diffuse
(6) Filterability	Pass through filter paper	passes through filter paper	can be separated by filter paper
Example	NaCI dissolved in water	Blood	Mud water.

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 settl on keeping, then it is a suspension.

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

Property	True solution	Colloidal solution	Suspension
(1) Appearance	homogeneous and transparent	Heterogeneous and translucent	heterogeneous and opaque
(2) particle size	< 1 nm (10-7 cm)	1 nm - 100 nm	> 100 nm (10-5 cm)
(3) Visibility	particles are not visible even with a powerful microscope	Particles can be seen with a high power microscope	particles can be seen with naked eyes
(4) Stability	Stable	Stable	Unstable
(5) Diffusion	Diffuse rapidly	Diffuse slowly	Do not diffuse
(6) Filterability	Pass through filter paper	passes through filter paper	can be separated by filter paper
Example	NaCI dissolved in water	Blood	Mud water.

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.

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

property	True solution	Colloidal solution	Suspension
(1) Appearance	homogeneous and transparent	Heterogeneous and translucent	heterogeneous and opaque
(2) particle size	< 1 nm (10-7 cm)	1 nm - 100 nm	> 100 nm (10-5 cm)
(3) Visibility	particles are not visible even with a powerful microscope	Particles can be seen with a high power microscope	particles can be seen with naked eyes
(4) Stability	Stable	Stable	Unstable
(5) Diffusion	Diffuse rapidly	Diffuse slowly	Do not diffuse
(6) Filterability	Pass through filter paper	passes through filter paper	can be separated by filter paper
Example	NaCI dissolved in water	Blood	Mud water.

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.

Various point of distinction between a chemical compound and a mixture are summarised below:

Characteristics	Pure substance or compound	Mixture
1. Composition	The elements in a compound are present in definite proportion by weight.	The ingredients of a mixture may be present in varying ratios.
2.Homogeneity	A compound is always homogeneous	A mixture may be homogeneous (solution) or heterogeneous.
3. Properties	A compound has entirely different properties from those of its constituents.	Properties of a mixture are an average of the properties of its constituents.
4. Separation	The constituents of a compound cannot be separated by simple separation techniques.	The constituents of a mixture can be separated by simple methods.
5. Energy changs	Energy in the form of heat, light, or electricity is either evolved or absorbed when a compound is formed	There is generally no energy change when a mixture is formed from its constituents.
6. volume change	At constant temperature and pressure, the formation of a compound may involve either no change or a large change in volume.	At constant temperature and pressure, the formation of a mixture involves either very little or no change in volume.

(i) Potassium chloride crystallises out.
(ii) Sugar remains as residue in the form of a solid mass.
(iii) A black coloured compound is formed.

A compound is a substance which is formd by the combination of two or more elements in a fixed proportion by weight. The properties of a compound are entirely different from its constituent. A compound can be decomposed into two or more simpler substances. For example, water is a compound formed by combination of 89% oxygen and 11% hydrogen by weight irrespectively of its source. Its properties namely, density, physical state, reactivity etc. are quite different from the properties of hydrogen and oxygen. Water can be oxygen, salt is made of sodium and chlorine and sugar is made of carbon, oxygen and hydrogen having their constituent elements in fixed proportions. Carbon dioxide, salt and sugar are compounds.

(a) (i) centrifugation        
(ii) filtration
(iii) Separating funnel      
(iv) Evaporation
(v) Sublimation              
(vi) Winnowing
(b) (i) Physical change    
(ii) Chemical change
(iii) Chemical change      
(iv) Physical change.

(a) A solution is a homogeneous mixture of two or more substances. Concentration of sulphuric acid solution = \({10\over 100}\times 100=\) 10% volume by volume.
(b) Solvent - water
Solution - salt solution
Suspension -sand grains
Colloid-unfilterable clay particles.

Homogeneous mixture Heterogeneous mixture (i) it has no visible boundary or boundaries of separation between its constituents. (i) It has visible boundary/boundaries of separation between its constituents. (ii) It has a uniform composition throughout its mass. (ii) The composition of the mixture varies from mass to mass (iii) It does not show the Tyndall effect (iii) It shows the Tyndall effect.

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