Class 9th Science Matter in Our Surroundings Practice Questions

Section A – Multiple Choice Questions (MCQs) [20 Questions × 1 mark = 20]

1. Which of the following is not matter?
   a) Air
   b) Chair
   c) Heat
   d) Water
2. SI unit of temperature is:
   a) Celsius
   b) Kelvin
   c) Fahrenheit
   d) Joule
3. Solid CO₂ is called:
   a) Dry ice
   b) Hard ice
   c) Solid oxygen
   d) None
4. Which state of matter has maximum kinetic energy?
   a) Solid
   b) Liquid
   c) Gas
   d) Plasma
5. Which process converts solid directly into vapour?
   a) Condensation
   b) Fusion
   c) Sublimation
   d) Boiling
6. Latent heat of fusion of ice is:
   a) 334 J/g
   b) 80 J/g
   c) 540 J/g
   d) 273 J/g
7. Evaporation is:
   a) Surface phenomenon
   b) Bulk phenomenon
   c) Slow condensation
   d) Freezing
8. Which state of matter has negligible intermolecular space?
   a) Solid
   b) Liquid
   c) Gas
   d) Plasma
9. Which of the following is not an example of diffusion?
   a) Smell of perfume
   b) Ink spreading in water
   c) Sugar dissolving in tea
   d) Melting of ice
10. When heat is supplied to a solid at its melting point, the temperature:
    a) Increases
    b) Decreases
    c) Remains constant
    d) Becomes zero
11. The phenomenon of conversion of water into vapour below boiling point is:
    a) Sublimation
    b) Boiling
    c) Evaporation
    d) Fusion
12. Which of the following does not affect evaporation?
    a) Temperature
    b) Surface area
    c) Colour of liquid
    d) Wind speed
13. Which of the following has fixed shape and volume?
    a) Solid
    b) Liquid
    c) Gas
    d) Plasma
14. Which state of matter has highest compressibility?
    a) Solid
    b) Liquid
    c) Gas
    d) Plasma
15. The smell of food being cooked spreads due to:
    a) Melting
    b) Diffusion
    c) Evaporation
    d) Condensation
16. Which of the following has no fixed volume?
    a) Solid
    b) Liquid
    c) Gas
    d) All
17. Which process is responsible for cooling in desert coolers?
    a) Condensation
    b) Freezing
    c) Evaporation
    d) Boiling
18. Plasma is formed at:
    a) Very low temperature
    b) Very high temperature
    c) At 0°C
    d) At 100°C
19. Particles of matter are held together by:
    a) Gravity
    b) Intermolecular force
    c) Pressure
    d) Friction
20. Dry ice is kept at:
    a) Room temperature
    b) 0°C
    c) -78°C
    d) 100°C

Section B – True/False [10 Questions × 1 mark = 10]

21. Matter is anything that has mass and occupies space.
22. Solids are highly compressible.
23. Evaporation causes cooling.
24. Gases have least intermolecular space.
25. Plasma and BEC are considered as states of matter.
26. Boiling is a surface phenomenon.
27. Diffusion is faster in gases than in solids.
28. Increasing humidity decreases evaporation.
29. Melting of ice is an example of condensation.
30. Latent heat is absorbed without change in temperature.

Section C – Fill in the Blanks [10 Questions × 1 mark = 10]

31. Matter is made up of ________.
32. The SI unit of pressure is ________.
33. The SI unit of temperature is ________.
34. The process of solid changing directly into gas is called ________.
35. The temperature at which a liquid boils is called ________.
36. Evaporation is faster on a ________ day.
37. ________ is the amount of heat energy required to change 1 kg of solid into liquid.
38. Dry ice is solid ________.
39. Diffusion becomes faster at ________ temperatures.
40. ________ phenomenon explains why perfume spreads in a room.

Section D – Assertion & Reason [10 Questions × 1 mark = 10]

41. A: Solids are incompressible.
    R: They have negligible intermolecular space.
42. A: Boiling is a bulk phenomenon.
    R: All particles of liquid take part in boiling.
43. A: Evaporation is a cooling process.
    R: Particles absorb heat from surroundings to escape.
44. A: Latent heat of fusion is absorbed during melting.
    R: Temperature remains constant during phase change.
45. A: Diffusion is faster in liquids than in gases.
    R: Liquids have less intermolecular space.
46. A: Ice at 0°C feels colder than water at 0°C.
    R: Ice absorbs latent heat of fusion.
47. A: Particles of matter are always at rest.
    R: They have negligible kinetic energy.
48. A: Solids have definite shape.
    R: They have strong intermolecular forces.
49. A: Evaporation depends on humidity.
    R: High humidity increases evaporation.
50. A: Temperature remains constant during boiling.
    R: Heat is used to break intermolecular forces.

Section E – Very Short Answer (1 Mark Each) [10 Questions = 10 Marks]

51. Define matter.
52. Write SI unit of temperature.
53. Give one property of particles of matter.
54. Name the process by which water vapour changes into liquid.
55. Define latent heat of fusion.
56. Why is ice called a solid?
57. Write one difference between evaporation and boiling.
58. What is the boiling point of water?
59. Write one example of sublimation.
60. Name two states of matter discovered recently.

Section F – Short Answer (2 Marks Each) [10 Questions = 20 Marks]

61. Why does evaporation cause cooling?
62. Why does a desert cooler work better on a hot dry day?
63. Why does camphor disappear when kept open?
64. Why do we see water droplets on the outer surface of a cold glass?
65. Give two factors affecting evaporation.
66. Why do clothes dry faster on a windy day?
67. Differentiate between solid and liquid (any 2 points).
68. What is meant by latent heat of vaporization?
69. Why do we sweat more on humid days?
70. Why does an earthen pot keep water cool?

Section G – Short Answer (3 Marks Each) [10 Questions = 30 Marks]

71. Distinguish between evaporation and boiling (3 points).
72. Explain why perfume spreads faster in a room.
73. Why does the temperature remain constant during the melting of ice?
74. Why do wet clothes dry faster in summer than in winter?
75. What is the effect of surface area on evaporation?
76. Why is diffusion faster in gases than in solids?
77. Give 3 properties of particles of matter.
78. Explain interconversion of states of matter with examples.
79. Why does water boil at a lower temperature in hilly areas?
80. Give reasons: (a) Steam causes severe burns than boiling water.
         (b) Ice at 0°C feels colder than water at 0°C.

Section H – Long Answer (4–5 Marks Each) [10 Questions = 40 Marks]

81. Explain factors affecting evaporation with examples.
82. Differentiate between solid, liquid and gas (any 4 points each).
83. Explain latent heat of fusion and vaporization with examples.
84. Why does temperature remain constant during boiling and melting?
85. Describe an activity to show that particles of matter are continuously moving.
86. Explain plasma and Bose-Einstein condensate with examples.
87. How can we show that matter is made of particles?
88. Explain why water kept in earthen pot becomes cool.
89. Write differences between evaporation and condensation (any 4).
90. Draw and explain a heating curve for ice.

Section I – Case Study Based [10 Questions × 2 marks = 20 Marks]

Case 1: Ramesh noticed that naphthalene balls in his cupboard became smaller with time.
91. Name the process responsible.
92. Why does this happen even at room temperature?

Case 2: Seema observed droplets of water on a cold water bottle kept outside.
93. Name the process.
94. Explain why this happens.

Case 3: Rahul spilled perfume in his classroom and within minutes the smell spread everywhere.
95. Which property of matter is demonstrated?
96. In which state of matter is diffusion fastest?

Case 4: Clothes dry quickly on a terrace during summer.
97. Which phenomenon is responsible?
98. Mention two factors that affect this process.

Case 5: A block of ice is kept in a beaker. Heat is supplied until it turns into vapour.
99. What happens to the temperature during melting?
100. Why does temperature remain constant during boiling?