CBSE 9th Chemistry | The Matter-Nature and Behaviour (Very Short Answer Type Questions)


The Matter-Nature and Behaviour (Very Short Answer Type Questions)

Question 1. The earlier Indian Philosophers classified matter in the form of five basic elements. Name these five elements.

Answer.

The five basic elements are : Air, Earth, Fire, Sky and Water.

Question 2. According to modern view is matter continuous or particulate?

Answer.

Matter is particulate in nature i.e., Matter is made up of particles.

Question 3. What is the size of particles of matter?

Answer.

The particles of matter are very small. They are small beyond our imagination.

Question 4. What is diffusion?

Answer.

The intermixing of particles of two substances on their own is called diffusion.

Question 5. What is the effect of temperature on the speed of particles of matter?

Answer.

As temperature rises, particles move faster i.e., the speed of particles increases.

Question 6. Name major characteristics of solid state of matter.

Answer.

Solid state is characterised by having a definite shape, distinct boundaries, rigidity and incompressibility.

Question 7. By what name is the space occupied by a substance known?

Answer.

The space occupied by a substance is called volume.

Question 8. What is the common unit of volume?

Answer.

The unit of volume is cubic meter (m3)

The common unit is litre  (L)

1L = 1dm3

= 1000 ml

Question 9. The particles of matter are always in motion and due to this motion they posses some energy. By what name is this energy known?

Answer.

The energy possessed by a particles by virtue of its motion is known as kinetic energy (K.E.).

Question 10. Why do solids have a rigid or fixed shape?

Answer.

The particles of solids only vibrate at their mean position and they possess a low kinetic energy. Due to this solids have a rigid or fixed shape.

Question 11. What are the characteristics of a liquid?

Answer.

The liquid state is characterised as having fluidity, low compressibility and no definite shape or boundaries.

Question 12. Are liquids rigid?

Answer.

No, liquids are not rigid. They are fluid because they can flow.

Question 13. Arrange the particles of solids, liquids and gases in the decreasing order of kinetic energy possessed by them.

Answer.

Gases > Liquids > Solids.

Question 14. How does diffusion varies with density of liquid?

Answer.

More the density lesser is diffusion.

Question 15. Name any property that is shown by naphthalene but not by sodium chloride.

Answer.

Both are solids but naphthalene is sublime substance and shows the property of sublimation. This property is not shown by sodium chloride.

Question 16. What is pressure at sea level?

Answer.

The pressure that exists at sea level is taken as 1 atmosphere or 760 mm of mercury.

Question 17. Zero °C represents the freezing point of water or the melting point of ice?

Answer.

It represents both freezing point as well as melting point.

Question 18. Boiling point of alcohol is 65°C. What is the boiling point of alcohol in Kelvin scale?

Answer.

65°C = (65 + 273)K=338K.

On kelvin scale the boiling point of alcohol is 338 K.

Question 19. Define condensation.

Answer.

It is the process of conversion of vapour (gas) to liquid on cooling (decreasing temperature).

Question 20. What is dry ice?

Answer.

Solid carbon di-oxide (C02) is known as dry ice.

Question 21. Why can’t the solids be compressed much?

Answer.

The intermolecular space between the particles of solids is very less, because of this solids can not be compressed much.

Question 22. Arrange the solids, liquids and gases in the increasing order of inter molecular forces of attraction.

Answer.

Gases < Liquids < Solids.

Question 23. Arrange the solids, liquids and gases in the decreasing order of interparticle space.

Answer.

Gases > Liquids > Solids.

Question 24. Why is the property of diffusion not shown by solids?

Answer.

Since the particles of solids do not move much so the solids do not show the property of diffusion.

Question 25. By what name is the substance known in case there occurs a diffusion of a solid in a solid which is a rare phenomenon.

Answer.

It is known as solid-solid solution or alloy.

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