most important questions for class 9th, science, chapter 1

  1. Discus the kinetic theory of matter.
  2. What is evaporation? Discus the factors that influence evaporation.
  3. Out of dry and wet air which is heavier.
  4. What is S.I. unit of density?
  5. Define latent heat of fusion.
  6. Is dry ice is same thing as of ordinary ice.
  7. What is lattice?
  8. How will you demonstrate that particles of matter have space b/w them.
  9. Why oxygen is called as gas.
  10. What do you understand by the process of diffusion? Give one example.
  11. State two properties of each solid, liquid and gas.
  12. Why oxygen is called gas. Give two reasons.
  13. What is plasma?
  14. What happens when solid is heated.
  15. Explain how it is possible to skate on ice without leaving trail behind.
  16. What is the difference b/w gas and vapour?
  17. If you decrease the surface area and increase the temperature, then the rate of evaporation  (a) increase  (b) decrease  (c) remain same  (d) may increase or decrease depending upon other factors
  18. 300k will have its corresponding temperature in degree centigrade as:-(a) 300c   (b) 3000c    (c) 270c   (d) 6730c
  19. Liquid to gas and gas to liquid changes are called:-(a) vaporization and condensation (b) condensation and vaporization (c) sublimation and condensation (d) condensation and sublimation
  20. Physical state of water at 250c, 00c and 1000c is respectively (a) liquid, solid and gas (b) solid, liquid and gas  (c) solid, gas and liquid  (d) gas, solid and liquid
  21. What happens when the temperature of the solids increase?
  22. When heat is being supplied to a solid, then what does the heat energy do to the particles of solid?