1. What are the three states of water?
a) Ice, Dew, Steam
b) Liquid, Solid, Vapour
c) Solid, Liquid, Gas
d) Water, Rain, Cloud
2. The process of converting water into vapour is called:
a) Melting
b) Evaporation
c) Condensation
d) Freezing
3. The reverse of condensation is:
a) Melting
b) Freezing
c) Evaporation
d) Sublimation
4. Sublimation is the process in which:
a) Liquid changes to gas
b) Solid changes directly to gas
c) Gas changes to solid
d) Liquid changes to solid
5. Water in this state has fixed volume but no fixed shape:
a) Solid
b) Liquid
c) Gas
d) Vapour
6. What happens to ice when heat is supplied?
a) It freezes
b) It evaporates
c) It melts
d) It sublimes
7. State of water with fixed volume but no fixed shape:
a) Solid
b) Liquid
c) Gas
d) Ice
8. Water vapour touching a cold surface forms:
a) Steam
b) Snow
c) Water droplets
d) Ice crystals
9. What happens to water when heated on stove?
a) It freezes
b) It boils forming vapour
c) It condenses
d) It sublimes
10. Which factor does not affect evaporation rate?
a) Humidity
b) Temperature
c) Air movement
d) Container shape
11. Why do clothes dry slower on a rainy day?
a) Sun is brighter
b) Water does not evaporate
c) High humidity reduces evaporation
d) Air is cooler
12. How to speed up evaporation?
a) Cover clothes
b) Put in fridge
c) Keep near sun or fan
d) Store in closed box
13. Why do clothes dry faster on a windy day?
a) Sunlight is more
b) Wind increases evaporation
c) Clouds absorb water
d) Air condenses water
14. What happens when rising water vapour cools?
a) It evaporates
b) It condenses into clouds
c) It solidifies into ice
d) It vanishes
15. Frost on cold mornings is:
a) Liquid form
b) Gas form
c) Solid form
d) Vapour form
16. Why is steam visible from boiling water?
a) Water turns into cloud
b) Water droplets condense in air
c) Water becomes ice
d) Water bubbles burst
17. Which is not part of water cycle?
a) Evaporation
b) Condensation
c) Precipitation
d) Sublimation
18. Water vapour cools and collects on grass at night as:
a) Snow
b) Dew
c) Frost
d) Rain
19. Why does ice float on water?
a) Heavier than water
b) Absorbs water
c) Contains air
d) Less dense than water
20. What happens if water bowl is left in sun?
a) Water freezes
b) Water evaporates completely
c) Water overflows
d) Water remains unchanged
21. Why do we see steam when hot water on cold surface?
a) Evaporation occurs
b) Condensation of vapour
c) Freezing
d) Precipitation
22. Why does water freeze faster in metal tray than plastic?
a) Plastic repels cold
b) Metal is good conductor of heat
c) Metal absorbs cold
d) Plastic absorbs heat
23. What happens to ice at room temperature?
a) Boils
b) Sublimes
c) Melts
d) Remains same
24. Why do wet clothes feel cooler than dry?
a) Wet clothes are heavy
b) Evaporation cools the surface
c) They block air
d) They don’t absorb sunlight
25. What happens to water at 0°C?
a) Evaporates
b) Melts
c) Freezes into ice
d) Condenses into vapour
26. Boiling point of water at normal pressure:
a) 0°C
b) 37°C
c) 100°C
d) 212°C
27. Sublimation is:
a) Liquid to solid
b) Solid to gas directly
c) Gas to liquid
d) Gas to solid
28. Which of the following is not a state of water?
a) Solid
b) Liquid
c) Gas
d) Plasma
29. The gaseous form of water is called:
a) Fog
b) Mist
c) Water vapour
d) Rain
30. What causes water to evaporate faster?
a) Cold temperature
b) No wind
c) Heat / Sunlight
d) Darkness
31. Melting is the conversion of:
a) Solid to gas
b) Liquid to gas
c) Solid to liquid
d) Gas to liquid
32. Which state of water can flow and take the shape of its container?
a) Solid
b) Liquid
c) Gas
d) Ice
33. When water vapour cools down, it becomes:
a) Ice
b) Water
c) Snow
d) Hailstones
34. Fog is formed due to:
a) Evaporation
b) Freezing
c) Melting
d) Condensation
35. The freezing point of water is:
a) 100°C
b) 25°C
c) 0°C
d) 50°C
36. Which state of water spreads in all directions?
a) Solid
b) Liquid
c) Gas
d) Ice
37. Evaporation occurs faster when:
a) Temperature is low
b) Air is still
c) It is cloudy
d) It is hot and windy
38. What happens to ice when left at room temperature?
a) It freezes
b) It melts into water
c) It evaporates immediately
d) It turns into gas directly
39. Why do water droplets appear on a cold glass?
a) Water leaks through the glass
b) Water condenses from air
c) Water seeps out from glass
d) Evaporation from inside
40. Water vapour on cooling turns into:
a) Snow
b) Ice
c) Water droplets
d) Frost
1.Answer: c) Solid, Liquid, Gas
2.Answer: b) Evaporation
3.Answer: c) Evaporation
4.Answer: b) Solid changes directly to gas
5.Answer: b) Liquid
6.Answer: c) It melts
7.Answer: b) Liquid
8.Answer: c) Water droplets
9.Answer: b) It boils forming vapour
10. Answer: d) Container shape
11Answer: c) High humidity reduces evaporation
12.Answer: c) Keep near sun or fan
13.Answer: b) Wind increases evaporation
14.Answer: b) It condenses into clouds
15.Answer: c) Solid form
16.Answer: b) Water droplets condense in air
17.Answer: d) Sublimation
18.Answer: b) Dew
19.Answer: d) Less dense than water
20.Answer: b) Water evaporates completely
21. Answer: b) Condensation of vapour
22.Answer: b) Metal is good conductor of heat
23Answer: c) Melts
24.Answer: b) Evaporation cools the surface
25. Answer: c) Freezes into ice
26.Answer: c) 100°C
27.Answer: b) Solid to gas directly
28.Answer: d) Plasma
29.Answer: c) Water vapour
30.Answer: c) Heat / Sunlight
31.Answer: c) Solid to liquid
32.Answer: b) Liquid
33.Answer: b) Water
34.Answer: d) Condensation
35.Answer: c) 0°C
36.Answer: c) Gas
37.Answer: d) It is hot and windy
38.Answer: b) It melts into water
39.Answer: b) Water condenses from air
40.Answer: c) Water droplets
1.
What are the three states of water?
Answer: Solid (ice), liquid (water), and gas (water vapour).
2.
What is the process of converting water into water vapour?
Answer: Evaporation.
3.
What happens to ice when it is left at room temperature?
Answer: Ice melts and becomes water.
4.
What is water vapour?
Answer: It is the gaseous form of water present in the air, usually invisible.
5.
What causes water droplets to appear on the outer surface of a cold glass?
Answer: Condensation of water vapour from the air on the cold surface.
7.
What is condensation?
Answer: The process of water vapour converting into liquid water.
8.
What is sublimation? Give an example.
Answer: Sublimation is the process in which a solid changes directly into a gas without becoming liquid first, e.g., naphthalene balls or dry ice.
9.
How does evaporation cause cooling? Give an example.
Answer: Evaporation takes heat away from the surface causing cooling, e.g., water in an earthen pot feeling cool, or sweat evaporating from the skin to cool the body.
10.
Explain the water cycle briefly.
Answer: Water evaporates from oceans, lakes, and rivers; water vapour condenses into clouds; clouds produce precipitation such as rain or snow; water flows back into water bodies; this cycle continues.
11.
Why do clothes dry slower on a rainy day?
Answer: Because humidity is high, reducing the rate of evaporation.
12.
What is freezing?
Answer: The process of converting liquid water into solid ice by cooling.
13.
Why does ice float on water?
Answer: Ice is less dense than water because it expands upon freezing.
15.
In what condition does water evaporate faster?
Answer: Water evaporates faster when the exposed surface area is larger, when air is hot, dry, and windy.
16.
What happens to water vapour when it rises high in the sky and cools?
Answer: Water vapour condenses to form clouds.
17.
What makes rain fall from the clouds?
Answer: When water droplets combine and become heavy enough, gravity causes the rain to fall.
18.
What is the effect of humidity on evaporation?
Answer: Higher humidity slows evaporation because the air already contains water vapour.
19.
How does an earthen pot keep water cool?
Answer: Water seeps through the pot’s pores and evaporates, drawing heat and cooling the water inside.
20.
What role do dust particles play in cloud formation?
Answer: Water vapour condenses around tiny dust particles to form clouds.
22. What makes water droplets appear on the outer surface of a glass with ice cubes?
Answer: Water vapor from the air condenses on the cold surface forming droplets.
23. What is humidity?
Answer: The amount of water vapor present in the air.
24. What happens to water vapor when it touches a cold surface?
Answer: It condenses into liquid water droplets.
25. What is the process of water changing to vapor called?
Answer: Evaporation.
26. What is condensation?
Answer: Conversion of water vapor into liquid water.
27. How does water evaporate faster?
Answer: When exposed surface area is larger, air is warm and windy.
28. Why does water feel cooler in an earthen pot?
Answer: Water seeps through pot’s pores and evaporates, cooling the water.
29. What is sublimation?
Answer: Conversion of solid directly into gas without becoming liquid.
30. Give an example of sublimation.
Answer: Naphthalene balls disappearing over time.
31. What is evaporation’s effect on cooling?
Answer: Evaporation absorbs heat from the surroundings causing cooling.
32. What is the state of water that flows and fills the shape of its container?
Answer: Liquid.
33. Which state of water spreads out to fill available space?
Answer: Gas (water vapor).
34. What happens when ice melts?
Answer: It turns into liquid water.
35. What causes rain?
Answer: Condensation causes water droplets to join and fall as rain.
36. Why do clothes dry slower on rainy days?
Answer: High humidity reduces evaporation rate.
37. Why do clothes dry faster on windy days?
Answer: Wind carries away water vapor speeding evaporation.
38. What role do dust particles play in cloud formation?
Answer: Water vapor condenses around dust particles forming clouds.
39. What is freezing?
Answer: Conversion of liquid water into solid ice.
40. Why does ice float on water?
Answer: Ice is less dense because it expands on freezing.
41. What is boiling point of water at normal pressure?
Answer: 100°C.
42. Why does water freeze slower if salt is added?
Answer: Salt lowers freezing point of water, delaying freezing.
43. Why do water pipes burst in winter?
Answer: Water expands as it freezes causing pipes to burst.
44. How does temperature affect evaporation?
Answer: Higher temperature increases evaporation rate.
45. How can you speed up drying on a rainy day?
Answer: Use a fan to increase air movement.
46. What is the water cycle?
Answer: Continuous movement of water evaporating, condensing, and precipitating.
47. Why is water important for plants and animals?
Answer: Water is essential for survival and metabolic processes.
48. What is the difference between dew and frost?
Answer: Dew is liquid water condensed from vapor; frost is frozen dew.