Napoleon Bonaparte Child of the Revolution

Matter In Our Sourroundings
Important Questions Not for coping to note
Q. 1. What is a matter?
Answer :
Anything that occupies space and has mass is called a matter.
For example:- Chalk, Milk, Sugar etc.

Q. 2. Sodium chloride and sugar have same appearance. Are they same or different?

Answer : They have different physical and chemical properties. So, they are different.

Q. 3. All substances around us are alike. How?

Answer : All substances can occupy space and have weight.

Q. 4. How can we say that air is a matter?

Answer : Air occupies space and have weight. Hence air is a matter.

Q. 5. State the characteristics of matter?

Answer : Matter has mass, weight and occupies space

Q. 6. What are the intensive properties of matter?

Answer : Density, colour, melting point, boiling point, refractive index etc. are the intensive properties of matter as it does not depend upon the amount of matter contained in it.

Q. 7. What are the extensive properties of matter?

Answer : The properties which depends upon the amount of matter contained in a substance is called extensive properties of matter. For example mass, weight, volume, energy etc.

Q. 8. State the characteristics of particles of matter.

Answer : (i) There is enough space between the particles of matter.
(ii) The particles of matter are continuously moving about their mean position.
(iii) The particles of matter attract each other.

Q. 9. What is the effect of temperature on a matter?

Answer : Particles of matter posses kinetic energy. As the temperature rises, kinetic energy increases.

Q. 10. The smell of hot sizzling food reaches us several metres away. Why?

Answer : As the rate of diffusion increases with the increase in temperature.

Q. 11. What is diffusion?

Answer : When two gases are mixed, their molecules mix with each other due to their speed and random motion. This phenomenon is known as diffusion.

Q. 12. If a bottle of perfume is opened in one corner of a room, it immediately spreads throughout the room. Why?

Answer : The molecules of a gas are free to move in a chaotic motion at a greater speed throughout the vessel in which it is contained. When the bottle of perfume is opened in one corner of the room, the molecules of perfume move at random motion in all direction and mix with the molecules of air and reaches us.

Q. 13. Name the three states of matter with examples.

Answer : The three states of matter are:
(i) Solid :- A solid has definite shape and volume.
Example – wood, metal, rubber.
(ii) Liquid :- A liquid has definite volume and its shape is the shape of the container.
Example – water, oil, petrol.
(iii) Gas :– A gas has neither a definite volume nor a definite shape.
Example – air, hydrogen, oxygen.

Q. 14. State the characteristics of solids.

Answer : Solids are rigid. The molecules of solids are packed closely and remain fixed at their position. The molecules of solids are packed closely and remain fixed at their position. The force of attraction between the molecules are very strong and hence they resist any change in their shape or volume.

Q. 15. What are the characteristics of liquids?

Answer : Liquids have definite volume but not a definite shape. They take the shape of a container in which they are stored. The molecules have weaker force of attraction than solids, and hence can flow easily.

Q. 16. What are the characteristics of gases?

Answer : Gases have neither definite volume nor definite shape. The molecules have very weak force of attraction and low density. They can be compressed to liquid state and flow in any direction.

Q. 17. What are fluids?

Answer : Substances having tendency to flow are called fluids. Liquids and gases are fluids.

Q. 18. Give one similarity between a liquid and a gas and one dissimilarity.

Answer : Similarity :- Both liquids and gases are fluids and they take the shape of the container.
Dissimilarity :- A gas can be compressed easily to a desired volume. A liquid can not be compressed easily. A small volume of gas occupies the whole space of the container. But the volume of liquid is fixed. A large volume of gas can be stored in a container of very small volume

Q. 19. Differentiate between solid, liquid and gas.

Answer : Q. 20. What property of gas is utilized when natural gas is supplied for vehicles.

Answer : High compressibility of gas is utilized and compressed it for supply for the vehicles in the name of CNG.

Q. 21. What are ‘intermolecular forces’? How are these related to the three states of matter ?

Answer : The force operating between the atoms or molecules of a matter is called intermolecular force. The intermolecular force in solid are strong. This keeps the constituent particles very close to each other. Due to this solids are rigid and incompressible. This also give ordered arrangement of the particles giving regular geometrical shape to the solid.
In liquid, intermolecular force is weak to give definite shape.
In gas, intermolecular force is negligible and so its constituents particles are free to move and occupy the available space

Q. 22. Separate the following substances in groups of high and low intermolecular force:
Ice, sulphur vapour, nitrogen, sugar, copper, air, salt, plastic.

Answer : High intermolecular forces :-
Ice, sugar, copper, salt, plastic
Low intermolecular forces :-
Sulphur vapour, nitrogen, air

Q. 23. Which of the following substances you expect strongest and in which weakest intermolecular force:
Water, alcohol, sugar, sodium chloride, carbon dioxide.

Answer : Sodium chloride – Strongest
Carbon dioxide – Weakest

Q. 24. Why are gases compressible but liquids not ?

Answer : The molecules of a gas are separated very far and there is a lot of empty space between them. Hence gases can be compressed easily. In liquids molecules are closer to each other and can be brought further closer only under very high pressure

Q. 25. How does the state of matter changes from solid to liquid and then to gas on heating ?

Answer : In solids particles are very close. When heat is given to solid, the distance between particles increases and it takes the shape of the container. On further heating the distance between the particles increases in such an extent that the molecules are free to move. This is a gaseous state.

Q. 26. How is pressure developed in a container full of a gas ?

Answer : Gaseous molecules are free to move in the container. The molecules collide with each other and with the wall of the container. On the wall the molecules exert force. The force per unit area is called the pressure of the gas.

Q. 27. What are the applications of interconversion of states of matter ?

Answer : The interconversion of states of matter is used to :
(i) generate electricity in thermal power plant.
(ii) separate nitrogen and oxygen from air by liquefaction.
(iii) prepare machine parts.
(iv) prepare room fresheners.
(v) prepare ice-creams.

Q.28. What happens to a gas if its intermolecular space is reduced ?

Answer : If the intermolecular distance between molecules of a gas is reduced, it changes to liquid. Further reduction it is changed to solid.

Q. 29. Which of the following substances is most compressible ?
CO2, H2O, NaCl.

Answer : CO2

Q. 30. Which property of a gas results in steady pressure of the gas ?

Answer : The constant bombardment of the gas molecules with the walls of the container.