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Suspensions are the heterogeneous mixtures of a solid and a liquid in which the solids do not dissolve, like mixtures of soil and water. 

Ex : Mixture of sand and water.

If the amount of solute present is more in a solution, then the solution is said to be a concentrated solution.

If the amount of solute is less in a solution, then it is called dilute solution.

If the amount of solute is more in a solution, then the solution is called concentrated solution.

The factor influence solubility are 

1. nature of solute 

2. nature of solvent 

3. temperature.

The process by which matter changes from one state to another and back to original state, without any change in its chemical composition is called interconversion state of matter.

Two factors responsible for change of state of matter are: change in

(i) Temperature (ii) Pressure

The factors affecting rate of dissolving are 

i) Temperature of solvent, 

ii) Size of solute particles, 

iii) Stirring of the solution.

(a) Water is a matter because it has mas and occupies space.

(b) Any matter which has a definite volume but no definite shape is called a liquid.

(c) Fluid can flow.

(d) The molecules are at a greater distance in gases compared to liquids.

(e) Water boils at 100 °C.

(f) The physical state of a substance, which has a fixed volume but no fixed shape is liquid.

(g) All matter is made up of tiny particles called atoms.

(h) Liquids have a definite Volume.

(i) The temperature at which a liquid boils is called the boiling point of that liquid.

(j) Molecules in a solid are packed very closely.

(k) Liquids have no definite shape.

(l) When a gas is cooled, its molecules loose energy.

(m) Matter is anything that has mass and occupies space.

(a) Water is a matter because it has mass and occupies space. 

(b) Any matter which has a definite volume but no definite shape is called a liquid. 

(c) Liquids and gases can flow. 

(d) The molecules are at a greater distance in gases compared to liquids. 

(e) Water boils at 100 °C. 

(f) The physical state of a substance, which has neither fixed volume nor fixed shape is a gas.

1. Water 

2. Hydro chloric Acid

3. Nitric Acid

Compounds and their uses :

The symbols in form of the geometrical shapes were those used by the ancient Greeks to represent the four basic elements around us such as earth, air, fire and water.

Physical properties of non - metals :

1 Physical state: 

Non – metals occur as solids, liquids or gases at normal temperature; for example sulphur, phosphorus occurs in solid state while bromine occurs in liquid state. Gases like oxygen, nitrogen, etc., occur in the gaseous state

2. Hardness: 

Non – metals are generally not hard except diamond, (a form of carbon).

3. Lustre:

Non – metals have a dull appearance; Graphite and iodine are exceptions as they are shiny and lustrous.

4. Density: 

Non – Metals are generally soft and have low densities. The exception here is diamond (a form of carbon) which’is the hardest naturally occurring substance.

5. Melting point and boiling point: 

Non – metals have low melting point and boiling point. However, carbon, silicon and boron are exceptions.

6. Tensile strength: 

Non – metals do not have tensile strength. However, carbon fiber (a form of carbon) is as tensile as steel.

7. Malleability: 

Non – metals are non-malleable. If hammered, they form a powdery mass. Actually non – metals in solid state are brittle in nature.

8. Ductility: 

Non – metals are not ductile. Carbon fibre is highly ductile.

9. Conductivity: 

Non – Metals are generally bad conductor of electricity. Graphite (a form of carbon) is exception.

10. Sonorous: 

Non – metals do not produce sound (non – sonorous) when hit

Correct answer is (b) Hg

1. The cooking utensils are made up of aluminium and brass because they are good conductors of heat. 

2. Aluminium will form a layer of protective oxide that prevents further reaction. Also aluminium is also relatively cheap and that is why it is used widely in making utensils.

Metals have the capacity to withstand strain without breaking. This property is called tensile strength. It is the property that owes the use of iron for the construction of railway tracks.

1. False - Sodium is a soft metal, it can be cut with a knife.

2. True

3. True

4. False - Tungsten has the highest tensile strength.

5. True

Metals can be drawn into thin wires. This property of metals is called ductility.

1. Because the molecules of the gas moves freely so it occupies the whole space the vessel. 

2. Camphor disappears after sometimes as its surface gains kinetic energy and gets directly converted into gas. The process of getting converted directly into gas without getting converted into liquid is called sublimation

The letter “J” is the only one not found on the periodic table. In some countries (eg: Norway, Poland, Sweden. Serbia, Croatia), the element iodine is known by the name jod.

Astatine is the rarest element on earth. Astatine is a naturally occurring semi - metal that results from the decay of uranium and thorium.

Correct answer is (c) Zinc

Reason : High purity sand almost entirely compose of silica.

The most ductile metals is platinum.

i. b 

ii. a 

iii. d 

iv. c

(c) Generally solids and gases

Correct answer is (c) Bromine

Milk shows Tyndall effect.

Demonstration : 

1. Prepare the milk, copper sulphate, salt and starch solutions in different beakers. 

2. Allow a beam of light through each of them. 

3. The path of the light beam is clearly visible to us through milk. 

4. The path of the light beam is not visible through remaining. 

5. This experiment will be effective if it is performed in a dark room.

• Take some thick milk in a test tube. 
• Pass a beam of light from torch or a laser light. 
• We cannot observe the path of light through the solution.

The solutions are : sea water, air and soda water.

Some more examples of homogeneous mixtures are sugar solution, lemon squash, fruit juices, syrups and tonics used in medicine, etc.

Kerosene and petrol are separated by using distillation process because the difference in boiling point is more than 25°C.

Correct answer is (c) sodium

The mixture of ammonium chloride and salt is a heterogeneous mixture. Even though these two are white in colour their particles do not mix.

• Generally elements are available in nature in the form of their ores. 
• Study of properties of elements lead to the development of civilization. 
• The efforts of early alchemists-up to and including Newton, Hennig Brand, Sir Humphry Davy are appreciable for their works in unearthing new elements. 
• The definition of element and compound given by Robert Boyle and Lavoisier lead to study the properties of elements and compounds.

(a) Water is a matter because it has mass and occupies space.

(b) Any matter which has a definite volume but no definite shape is called a liquid.

(c) Fluid can flow.

(d) The molecules are at a greater distance in gases compared to liquids.

(e) Water boils at 100 °C.

(f) The physical state of a substance, which has a fixed volume but no fixed shape is liquid.

(g) All matter is made up of tiny particles called atoms.

(h) Liquids have a definite Volume.

(i) The temperature at which a liquid boils is called the boiling point of that liquid.

(j) Molecules in a solid are packed very closely.

(k) Liquids have no definite shape.

(l) When a gas is cooled, its molecules loose energy.

(m) Matter is anything that has mass and occupies space.

(a) True 

(b) True 

(c) False 

Correct: Solids have the very small (negligible) inter-molecular space. 

(d) False 

Correct : There is a difference between evaporation and boiling. 

(e) False 

Correct : Few solids, on heating, first change to the liquid and then to the gaseous state always. 

(f) True 

(g) True

If the amount of solute present is little, the solution is said to be dilute.

(a) True

(b) True

(c) False

(d) False

(e) False

(f) True

(g) True

(h) False

(a) Liquid

(b) Solid

(c) Gas

To separate two or more miscible liquids when the difference in their boiling points is less than 25°C, fractional distillation process is used.

On being hit, metals produce a typical sound. They are said to be sonorous. This property is being made used in making bells.

Oxygen is essential for our life and all living beings inhale it during breathing.

Sodium (Na) and Potassium (K) are soft metals those metals can be cut with a knife.

(a) Cohesive force : The force of attraction between particles of the same substance is called cohesive force.

(b) Diffusion: The phenomenon of intermixing of particles of one kind with another kind is called diffusion. 

(c) Brownian movement: The zig-zag motion of particles suspended in a medium is called Brownian movement