9th Sample Guess Extra score solved paper Matter in Our Surroundings

Class IX, Chemistry Solved Questions Chapter 1: Matter in Our Surroundings

1. what are the states of Matter around us?

Ans The matter around us exists in three states— solid, liquid and gas.

2. In which state of matter there will be maximum force of attraction between particles?

Ans. The maximum forces of attraction between the particles will be in Solid state.

3. In which state of matter there will be maximum kinetic energy of the particles?

Ans The maximum kinetic energy of the particles will be in gaseous state of matter.

4.What do you mean by Sublimation

Ans Sublimation is the change of gaseous state directly to solid state without going through liquid state, and vice versa.

5. What do you mean by Latent heat of vaporization?

Ans Latent heat of vaporization is the heat energy required to change1 kg of a liquid to gas at atmospheric pressure at its boiling point.

6. What do you mean by Latent heat of fusion?

Ans Latent heat of fusion is the amount of heat energy required to change 1 kg of solid into liquid at its melting point.

7. In which unit pressure is measured?

Ans. Pascal.

8. Convert the 5730 K temperatures to the Celsius scale.

Ans 573-273=3000 Celsius.

9. What is the physical state of water a 25­­0 C?

Ans Liquid state.

10. What produces more severe burns, boiling water or steam and why?

Ans Steam as it also has energy of latent heat of vaporization.

11. What is the unit of measurement of volume?

Ans cubic metre.

12. What are the Characteristics of Particles of Matter?

Ans Particles of matter have space between them, particles of matter attract each other and particles of matter are continuously in movement.

13. Arrange the following substances in increasing order of forces of attraction between the particles— water, sugar, oxygen?

Ans Oxygen –water –sugar.

15. Why should we wear cotton clothes in summer?

Ans During summer, we perspire more. And as 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 vaporization 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.