NCERT Question-Answer Solution for Class 6 Science Chapter 8 – A Journey Through States of Water
Complete NCERT Question–Answer Set for Class 6 Science (Curiosity Textbook) – Chapter 8: A Journey Through States of Water
Class 6 Science NCERT Solution – Chapter 8: A Journey Through States of Water
A Journey Through States of Water – Full NCERT Question–Answer Set (CBSE Class 6 Science – Curiosity Book)
SECTION 1: NCERT Back Exercise Questions with Answers
Q1. Which of the following best describes condensation?
(iv) The conversion of water vapour into its liquid state.
Q2. In which process is evaporation important?
(i) Water colours
(ii) Ink pen
Q3. Why does natural grass keep the surroundings cooler than plastic grass?
Answer:
Natural grass contains water.
Water continuously evaporates, causing a cooling effect.
Plastic grass does not allow evaporation, so no cooling happens.
Q4. Give examples of liquids other than water that evaporate.
Answer:
Perfume, petrol, kerosene, deodorant, alcohol, sanitizer.
Q5. Why does a fan help dry clothes even though it produces cool air?
Answer:
A fan increases the movement of air, which carries away water vapour faster.
Faster evaporation dries the clothes.
Q6. Why is sludge kept near drains for a few days before transporting?
Answer:
Because the water evaporates from the sludge, reducing its weight and making transportation easier and safer.
Q7. Identify evaporation activities at home.
Answer:
Drying clothes, drying mopped floor, drying dishes, drying sweat, boiling water, keeping wet grains in sunlight.
Q8. How is water present in solid form in nature?
Answer:
As ice in glaciers, icebergs, hailstones, and snow on mountains.
Q9. “Water is our responsibility before it is our right.” Explain.
Answer:
We should use water wisely because it is limited.
We must prevent wastage and keep water bodies pollution-free so everyone can use clean water.
Q10. The seat of a two-wheeler is very hot. How can you cool it?
Answer:
Sprinkle some water on the seat.
The water evaporates and produces a cooling effect.
SECTION 2: In-Chapter-Text Questions with Answers
Q1. Aavi has a counterview that ice and water are the same substance. What do you think? Why?
Answer:
Ice and water are the same substance because both are made of water. Ice is the solid state of water, and when it melts, it becomes water again. This shows they are simply two different forms of the same substance.
Q2. Thirav says something gets added to the water in the freezer to make ice. Is he right? How can you find out?
Answer:
No, nothing gets added to water in the freezer. Only the temperature decreases, causing water to freeze into ice.
To check, freeze clean water and then melt the ice. You will get exactly the same water back.
Activity 8.1 Question:
Q3. Ice melts into water. What can you conclude? Are ice and water the same substance?
Answer:
Yes. Ice and water are the same substance; they are just two different states of water. Ice is solid; water is liquid.
Q4. Water in puddles disappears. Where does it go?
Answer:
The water evaporates into water vapour and mixes with the air.
Q5. After washing utensils, water disappears from their surface. Why?
Answer:
Because the water evaporates into the air.
Q6. Does water seep through a steel plate in Activity 8.2? Where does the water go?
Answer:
Water does not seep through the steel plate.
The water evaporates and turns into water vapour.
Q7. When sprinkling water on a hot pan, it disappears. Where does it go?
Answer:
The water rapidly evaporates and forms water vapour (steam).
Q8. What is evaporation?
Answer:
Evaporation is the process by which water changes into water vapour.
Q9. What are examples of evaporation in daily life?
Answer:
Drying clothes, drying mopped floor, drying sweat from the body, drying wet soil.
Activity 8.3 Question:
Q10. Water droplets appear on the outer surface of a glass filled with cold water. Where do they come from?
Answer:
The droplets come from the water vapour present in the air. The vapour condenses when it touches the cold surface.
Q11. What is condensation?
Answer:
Condensation is the process by which water vapour turns into liquid water.
Q12. Why do we see dew drops more in the morning?
Answer:
Because nights are cooler, and the water vapour in the air condenses on cool surfaces to form dew.
Activity 8.4 Question:
Q13. Why does the mass of a cold glass with ice increase after some time?
Answer:
Because water vapour condenses on the cold surface and adds extra water droplets, increasing the mass.
Q14. Does water seep out of the glass in Activity 8.4? How do we know?
Answer:
No, water does not seep out.
The water level inside the glass remains unchanged, proving the water outside is formed by condensation.
Activity 8.5 Questions:
Q15. Compare ice, water and water vapour in terms of shape.
Answer:
Ice has a fixed shape.
Water takes the shape of the container.
Water vapour spreads to fill all available space.
Q16. Does ice flow? Does water flow? Does water vapour flow?
Answer:
Ice does not flow.
Water flows.
Water vapour spreads out in all directions.
Q17. Why can we smell food cooking even from far away?
Answer:
Because gases spread in air. Water vapour and food vapours mix and travel through air to reach our nose.
Q18. What is melting?
Answer:
Melting is the process of changing a solid into a liquid by heating.
Q19. What is freezing?
Answer:
Freezing is the process of changing a liquid into a solid by cooling.
Activity 8.6 Questions (State Change Diagram):
Q20. Fill the boxes (A, B, C):
A = Solid
B = Liquid
C = Gas
Processes:
- Melts
- Freezes
- Evaporates
- Condenses
SECTION 3: Higher-Order Thinking Questions (With Answers)
Q1. Why do clothes dry slowly on a rainy day?
Answer:
Because the air already contains a lot of water vapour (high humidity).
Less evaporation takes place.
Q2. Why does sweating cool our body?
Answer:
Sweat evaporates by taking heat from our body, producing a cooling effect.
Q3. Why do water droplets form inside the lid when boiling water?
Answer:
Because the steam (water vapour) touches the cool lid and condenses to form droplets.
Q4. Why does water vapour rise up in the air?
Answer:
Because water vapour is lighter than air.
Q5. Why does water in an earthen pot feel cool?
Answer:
Water seeps through tiny pores and evaporates from the outer surface, causing cooling.
SECTION 4: Long Answer Questions
Q1. Explain the water cycle.
Answer:
The water cycle describes how water moves continuously in nature.
Water evaporates from oceans, lakes and rivers, rises and cools to form clouds by condensation. When water droplets become heavy, they fall as rain, hail or snow. The water flows back to water bodies, completing the cycle.
Q2. Describe conditions that increase or decrease evaporation.
Answer:
Factors increasing evaporation:
Higher temperature
More air movement (wind)
Larger exposed surface area
Less humidity
Factors decreasing evaporation:
Low temperature
Less air movement
Small surface area
High humidity