MORE ABOUT SOLIDS, LIQUIDS AND GASES I. Tick (II) the most appropriate answer. 1. The fluid used in barometer is: (a) water (b) mercury (c) air 2. The normal atmospheric pressure is:

(d) none of these

(a) 70 cm of mercury

(b)

76 cm of mercury

(c) 67 cm of mercury

(d)

80 cm of mercury

3. The intermolecular spaces in case of liquids is: (a) less than solids (b) more than gases (c) more than solids (d) more than solids and gases 4. The kinetic energy of molecules of a gas increases with : (a) fall in temperature (b) rise in temperature (c) decrease in pressure (d) increase in pressure 5. The pressure exe1ted at any point on an enclosed liquid is transmitted: (a) only towards the sides of vessel (b) only towards the base of vessel (c) in all directions of the vessel (d) none of these 6. When a body is fully immersed in liquid, the apparent loss in the weight of the body is equal to: (a) volume of liquid displaced by body (b) density of the liquid (c) weight of liquid displaced by body (d) none of these 7. When an ink fountain pen leaks on high altitude: (a) pressure of atmosphere is more than pressure inside the pen (b) pressure of atmosphere is less than pressure inside the pen (c) the density of ink on high altitude decreases (d) none of these 8. When the weight of a given body is less than weight of fluid displaced by it, then the body:

9.

10.

11.

12. 13.

14.

15.

16.

(a) sinks (b) floats (c) just keeps in line with the surface of fluid (d) none of these Buoyant force exerted by a fluid on a given body is: (a) equal to the volume of body (b) equal to the weight of body (c) equal to the volume of fluid displaced by body (b) equal to the weight of fluid displaced by the body Heat is transmitted in liquids by: (a) conduction (b) convection (c) both conduction and convection (d) none of these A device to measure the liquid pressure is: (a) barometer (b) thermometer (c) manometer (d) lactometer The liquid used in a simple barometer is: (a) water (b) alcohol (c) mercury (d) kerosene Liquid pressure with increasing depth: (a) decreases (b) remains the same (c) increases (d) none of these The pressure exerted at any point on an enclosed liquid is transmitted: (a) only at the bottom (b) only on the sides (c) in all directions (d) none of these Buoyant force experienced by a body partly or wholly immersed in a fluid is called: (a) upward force (b) horizontal force (c) downward force (d) none of these Buoyant force exerted by a fluid on a body is equal to the (a) weight of the body: (b) apparent loss of weight of the body (c) mass of the body (d) none of these

17. If the weight of the body is more than the weight of fluid displaced by it, then the body: (a) float (b) first floats and then sinks (c) sinks (d) none of these

II. Fill in the blanks. 1. Kinetic energy of the molecules -----with the increase in temperature. 2. With the increase in ------ the inte1molecular forces decrease. 3. The Phenomenon due to which exposed surface of a liquid behaves like stretched membrane is called -----4. Mercury forms spherical droplets , because it has no force of with glass surface. 5. The meniscus formed by water in a test tube is of _ shape. 6. With the increase in the volume of an enclosed gas, its pressure 7. Convection in liquids takes place due to of its molecules. 8. The pressure in liquids is independent of of vessel 9. The atmospheric pressure at sea level is 100,000 _ 10. When a solid floats in a liquid, then the weight of whole _ is equal to the weight of liquid displaced by its immersed part. 11. All matter is made up of _ 12. Molecules of the same type each other. 13. A liquid droplet is in the shape of a _ 14. When a substance is heated, the kinetic energy of the molecules 15. When a gas is allowed to expand at a constant temperature its

pressure

_

16. Liquid pressure does not depend upon _ 17. For an object floating in water, its apparent loss of weight will be buoyant force. 18. The atmospheric pressure at sea level is mm- Hg. 19. Liquid pressure remains the in all directions at a given depth. 20. Pressure exerted by the liquids on the sides of the containing vessel is called -----21. At high altitudes, the atmospheric pressure _ 22. The force of attraction between the molecules of different substances is called force. 23. The force of attraction between molecules of the same substance is called -----24. If the weight of a body is equal to the buoyant force, it will _ in the fluid. 25. A submarine can sink or rise up by filling or emptying its _ 26. A brick feels in water than in air. 27. An iceberg is considered dangerous because it floats with only of its volume above water. -----28. Buoyant force is equal to the loss of of the body when it is immersed in a fluid. 29. The upward force exerted by a liquid on an object immersed in it, is called -----30. Mass per unit is called the _ 31. Larger the volume of a body immersed in a liquid the _ is the up thrust. 32. When the weight of a body is less than the weight of the liquid displaced by it, the body will _ 33. When the weight of a body is greater than the weight of the liquid

displaced by it, the body will

_

III. The statements given below are incorrect, write the correct statements. 1. When a solid floats in a liquid then the density of solid is always more than the density of liquid. 2. When the tube of a barometer is tilted, it records a different atmospheric pressure. 3. Molecule is the smallest unit of matter, which may or may not have an independent existence, but always takes part in a chemical reaction. 4. Meniscus is formed in the liquids due to the force of gravity. 5. Buoyant force of a liquid increases with the decrease in the density of liquid. 6. The pressure of an enclosed gas increases with the increase in the volume of gas. 7. Liquids exert same pressure in all directions at different depths.

8. Moisture in mercury increases the barometric height. 9. When a solid is completely immersed in a t1uid, then the apparent loss of weight of solid is more than the weight of fluid displaced. 10. Solids can be compressed because the molecules are arranged close together. 11. The relation between the up thrust and the weight of the liquid displaced by a submerged object was first discovered by a Greek mathematician and scientist named Aristotle. 12. Objects appear heavier when kept immersed in a fluid. 13. Buoyant force is experienced only when objects are immersed in liquids and not in gases. 14. Buoyant force acts in all directions. 15. The barometer reading changes for different positions at the same depth. 16. Atmospheric pressure increases as we move from sea level to higher altitude.

17. Conduction takes place due to molecular movement. 18. With the decrease in intermolecular space, the inte1molecular forces decrease. 19. Aneroid barometer used pure mercury. 20. With the decrease in the volume of gas its pressure decreases. IV. Name the following. 1. The scientist who first proposed that molecules are constantly moving. 2. The force between the molecules of two different types of substances. 3. The state of matter in which it is easily compressible. 4. The curve surface of a liquid column. 5. A mode of heat transference accompanied by the physical movement of molecules. 6. The upward force experienced by an object when immersed in a fluid.

7. The instrument used to measure atmospheric pressure.

V. Define these terms. 1. Surface tension 2. Cohesion 3. Adhesion 4. Atmospheric pressure 5. Conduction 6. Convection 7. Meniscus VI. Match the following. 1. Intermolecular force 2. Cohesion 3. Adhesion 4. Liquid pressure

(a) force of attraction between molecules of the substance (b) distribution of thrust exerted by a liquid due to its own weight (c) force of attraction between molecules (d) force of attraction between molecules of different substances

VII. Differentiate between the following. 1. Solids and liquids on the basis of arrangement of molecules.

2. Conduction and convection. 3. Liquid pressure and atmospheric pressure. VIII. Give reasons for the following. 1. Mercury does not "wet" glass. 2. The sides of an empty can do not collapse inwards. 3. You will be able to lift a heavy object quite easily inside water. 4. If a thermometer is broken, small drops of mercury will roll like little balls. 5. A gas can be easily compressed. 6. Water has a tendency to form spherical droplets. 7. Hydrogen-filled balloons tend to float upwards. 8. Giant hot-air balloons rise up. 9. A piece of iron floats in mercury but sinks in water. 10. A balloon filled with helium gas rises up. 11. One find easier to swim in sea water as compared to pure swimming pool water. 12. Only a tip of iceberg visible outside the water surface. IX. Answer the following questions. 1. State three factors which determine pressure in liquids.

2. Describe an experiment to prove that lateral pressure in liquids is directly proportional to the depth of liquid. 3. Define the following terms: (a) element (b) atom (c) molecule. 4. State five important points of kinetic theory of matter.

5. On the basis of kinetic the01y of matter explain. (a) Why the solids have a definite volume and definite shape? (b) Why the liquids have a definite volume but no definite shape? (c) Why the gases have no definite volume and no definite shape? 6. (a) What do you understand by the term surface tension? (b) Name the force responsible for surface tension. (c) Why does a small amount of mercury on placing over a glass plate form a spherical ball? (d) Why does a small amount of water on placing over a glass place form an oval shaped drop? 7. What do you understand by the term meniscus? Name the kind of meniscus formed (a) in case of water (b) in case of mercury. 8. Liquids exert pressure. Explain on the basis of kinetic model. 9. Gases exert pressure. Explain on the basis of kinetic model. 10. How does the pressure of an enclosed gas change with the decrease in volume? Explain it on the basis of kinetic model of matter. 11. Solids get heated by conduction. Explain conduction on the basis of kinetic model of matter. 12. Fluids get heated by convection. Explain convection on the basis of kinetic model of matter. 13. How does liquid pressure , depends upon the following? (a) depth of liquid (b) density of liquid (c) acceleration due to gravity at a given place (d) area of cross-section of the containing vessel 14. Why are the walls of a hydroelectric dam made thick at the base of dam?

15. Why do the deep sea divers wear specially designed suits? 16. What do you understand by the term atmospheric pressure? What is its average value at sea level? 17. The atmospheric pressure at sea level is 76 cm of mercury. What do you understand by the statement. 18. Describe briefly the construction of simple barometer? 19. What do you understand by the term buoyancy and buoyant force? State two factors which determine the buoyant force exerted by a liquid.

20. How does the atmospheric pressure decrease clue to change in altitude? 21. (a) State Archimedes ' Principle. (b) Briefly describe, how will you verify Archimedes 'Principle. 22. (a) State the law of floatation. (b) Why does ice float on the surface of water? 23. Why do ink pens start leaking on high altitude? 24. Why is the hearing affected while coming down from hills? 25. State Pascal's law? 26. A piece of iron sinks in water but large ships made of iron float on water. Explain why? 27. Why is mercury used in a barometer?

28. What are the defects of a simple mercury barometer? 29. When a solid substance is heated, what happens to its molecule? 30. Why are liquids and gases called fluids?