CBSE – 9th Standard Science

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Class 9 Question Bank Chapter 1 – Matter in our surrounding

Q1. What is matter made up of?

Ans. Matter is made up of small particles.

Q2. What are the different states of matter?

Ans. Solid, Liquid, Gas.

Q3. The force of attraction between the particles is maximum in which state?

Ans. The forces of attraction between the particles are maximum in solids.

Q4. The force of attraction between the particles is intermediate in which state?

Ans. The force of attraction between the particles is intermediate in Liquid

Q5. The force of attraction between the particles is minimum in which state?

Ans. The force of attraction between the particles is intermediate in gaseous state.

Q6. What do you mean by sublimation?

Ans. Sublimation is the change of gaseous state directly to solid state

Q7. What is boiling?

Ans. Particles from the whole of the liquid change into vapour state.

Q8. The rate of evaporation depends upon which factors?

Ans. The rate of evaporation depends upon the surface area exposed to the atmosphere, the temperature etc.

Q9. What do you mean by evaporation?

Ans. change of a liquid into vapours at any temperature is called evaporation.

Q10. What causes cooling?

Ans. Evaporation causes cooling.

Q11. On increasing the temperature of solids, which energy of the particles increases?

Ans. On increasing the temperature of solids, the kinetic energy of the particles increases.

Q12. What is the boiling point of water?

Ans. Boiling point of water is 100 degree Celsius

Q13. What is LPG?

Ans. LPG stands for Liquefied petroleum gas

Q14. What is CNG?

Ans. CNG stands for compressed natural gas.

Q15. Can matter change its state?

Ans. Yes matter can change its state.

Q16. What is the S.I unit of temperature?

Ans. S.I unit of temperature is Kelvin.

Q17. What is atmospheric pressure?

Ans. The pressure of air in atmosphere is called atmospheric pressure.

Q18. What is humidity?

Ans. Humidity is the amount of water vapour present in air.

Q19. What are the two states of matter except solid, liquid and gas?

Ans. They are Plasma and Bose-Einstein Condensate.

Q20. What daily use things consist of plasma?

Ans. The fluorescent tube and neon sign bulbs consist of plasma.

Q 21. Why should we wear cotton clothes in summer?

During summer, we perspire more because of the mechanism of our body which keeps us cool. We know that during evaporation, the particles at the surface of the liquid gain energy from the surroundings or body surface and change into vapour. The heat energy equal to the latent heat of vaporisation is absorbed from the body leaving the body cool. Cotton, being a good absorber of water helps in absorbing the sweat and exposing it to the atmosphere for easy evaporation.

Q.22. Why do we see water droplets on the outer surface of a glass containing ice-cold water?

 Let us take some ice-cold water in a tumbler. Soon we will see water droplets on the outer surface of the tumbler. The water vapour present in air, on coming in contact with the cold glass of water, loses energy and gets converted to liquid state, which we see as water droplets.

TRY THESE :-

 Q 1. A diver is able to cut through water in a swimming pool. Which

property of matter does this observation show?

Q.2.  What are the characteristics of the particles of matter?

Q.3. Give reasons

  • A gas fills completely the vessel in which it is kept.
  • A gas exerts pressure on the walls of the container.
  • A wooden table should be called a solid.
  • We can easily move our hand in air but to do the same through a solid block of wood we need a karate expert.
  • (e)The smell of hot sizzling food reaches you several meters away, but to get the smell from cold food you have to go close.