Not for coping to note
Q. 1. What is a matter?
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...