Chapter 7 Solutions — Particulate Nature of Matter

Keep the Curiosity Alive

1. 1.
   Choose the correct option. The primary difference between solids and liquids is that the constituent particles are:

   • (i) closely packed in solids, while they are stationary in liquids.
   • (ii) far apart in solids and have fixed position in liquids.
   • (iii) always moving in solids and have fixed position in liquids.
   • (iv) closely packed in solids and move past each other in liquids.
2. 2.
   Which of the following statements are true? Correct the false statements.

   • (i) Melting ice into water is an example of the transformation of a solid into a liquid.
   • (ii) Melting process involves a decrease in interparticle attractions during the transformation.
   • (iii) Solids have a fixed shape and a fixed volume.
   • (iv) The interparticle interactions in solids are very strong, and the interparticle…
3. 3.
   Choose the correct answer with justification. If we could remove all the constituent particles from a chair, what would happen?

   • (i) Nothing will change.
   • (ii) The chair will weigh less due to lost particles.
   • (iii) Nothing of the chair will remain.
4. 4.
   Why do gases mix easily, while solids do not?
5. 5.
   When spilled on the table, milk in a glass tumbler flows and spreads out, but the glass tumbler stays in the same shape. Justify this statement.
6. 6.
   Represent diagrammatically the changes in the arrangement of particles as ice melts and transforms into water vapour.
7. 7.
   Draw a picture representing particles present in the following:

   • (i) Aluminium foil
   • (ii) Glycerin
   • (iii) Methane gas
8. 8.
   Observe Fig. 7.16a which shows the image of a candle that was just extinguished after burning for some time. Identify the different states of wax in the figure and match them with Fig. 7.16b showing the arrangement of particles.
9. 9.
   Why does the water in the ocean taste salty, even though the salt is not visible? Explain.
10. 10.
    Grains of rice and rice flour take the shape of the container when placed in different jars. Are they solids or liquids? Explain.