Extra Questions for Chapter 8 A Journey through States of Water Class 6 Science Curiosity
Class 6 Science A Journey through States of Water Extra Questions
Multiple Choice Questions (MCQ)
Question 1. What is the process of water turning into vapour called?
(a) Condensation
(b) Evaporation
(c) Freezing
(d) Melting
Answer
(b) Evaporation
Evaporation is the process where liquid water changes into water vapour due to heat energy. This occurs when molecules in the liquid gain enough energy to escape into the air as gas.
Question 2. Which state of water does not have a fixed shape?
(a) Ice
(b) Water
(c) Water vapor
(d) Both b and c
Answer
(d) Both b and c
Both liquid water (b) and water vapour (c) do not have a fixed shape. Water takes the shape of its container in liquid form, and water vapour is in the gaseous form, which also adapts to the shape of its container.
Question 3. What happens to water vapour when it cools down?
(a) It disappears
(b) It condenses into liquid
(c) It becomes ice
(d) It evaporates
Answer
(b) It condenses into liquid
When water vapour cools down, it loses energy and condenses back into liquid form, typically observed as droplets on surfaces like windows or fog.
Question 4. Which of the following factors does NOT affect the rate of evaporation?
(a) Temperature
(b) Humidity
(c) Altitude
(d) Surface area
Answer
(c) Altitude
Temperature, humidity, and surface area all influence the rate of evaporation. However, altitude mainly affects air pressure, which has a smaller impact on evaporation compared to the other factors.
Question 5. What device collects moisture from humid air to produce drinkable water?
(a) Dehumidifier
(b) Atmospheric Water Generator
(c) Air conditioner
(d) Evaporator
Answer
(b) Atmospheric Water Generator
An Atmospheric Water Generator (AWG) collects moisture from the air and condenses it to produce purified, drinkable water.
Fill in the Blanks
1. The process of changing from a solid to a liquid is called _____.
2. Water vapour is _____ when it cools to form water droplets.
3. _____ refers to the amount of water vapor present in the air.
4. Ice is the _____ state of water.
5. Evaporation occurs faster at _____ temperatures.
Answer
1. Melting
2. Condensed
3. Humidity
4. Solid
5. Higher
True or False
1. Ice and water are the same substance in different states.
2. Water vapor is visible in the air.
3. Water can change states by adding or removing heat.
4. Higher humidity results in drier air.
5. Evaporation has a cooling effect on the surroundings.
Answer
1. True
2. False
3. True
4. False
5. True
Match the Following
|
Column A |
Column B |
|
1. Evaporation |
A. Process of changing from gas to liquid |
|
2. Condensation |
B. Process of changing from liquid to gas |
|
3.Himidity |
C. Amount of water vapour in the air |
|
4. Melting |
D. Process of changing from liquid to solid |
|
5. Freezing |
E. Process of changing from solid to liquid |
Answer
|
Column A |
Column B |
|
1. Evaporation |
B. Process of changing from liquid to gas |
|
2. Condensation |
A. Process of changing from gas to liquid |
|
3.Himidity |
C. Amount of water vapour in the air |
|
4. Melting |
E. Process of changing from solid to liquid |
|
5. Freezing |
D. Process of changing from liquid to solid |
One Word Answer
Question 1. What are the three states of water?
Answer
Solid, liquid, and gas.
Question 2. Name the phenomenon involved in fog formation during winters.
Answer
Condensation
Question 3. Name a substance that can be observed in three different states.
Answer
Water
Question 4. While making dosa, we sprinkle some water on the hot pan. Soon it disappears. Where does it go?
Answer
It converts into steam.
Question 5. Why cannot we use ocean water directly for drinking purpose?
Answer
It is salty impure water.
Question 6. How can we change water's state?
Answer
By adding or removing heat.
Question 7. Name the natural processes leading to water cycle.
Answer
Evaporation and condensation.
Very Short Answer Questions
Question 1. Where does hand sanitizer disappear as you rub it in your hands?
Answer
It disappears due to evaporation because on rubbing hands heat is produced.
Question 2. What is water primarily composed of?
Answer
Water is composed of hydrogen and oxygen.
Question 3. Are ice and water the same substance?
Answer
Yes, they are different states of the same substance.
Question 4. How do the areas covered with concrete affect the availability of ground water?
Answer
Areas covered with concrete reduce the seepage of rain water into the ground and this reduces the availability of ground water.
Question 5. What happens to water on a hot pan?
Answer
It converts to steam, which is water vapour.
Question 6. What is the process of water turning into vapour called?
Answer
The process is called evaporation.
Question 3.Water kept in sunlight gets heat from sun and is evaporated. But how does water kept under the shade of a tree also get evaporated? Explain.
Answer
Air around us gets heated from sunlight. This warm air provides heat for evaporation of water kept in the shade.
Question 4. Why do puddles disappear on warm days?
Answer
Due to evaporation and water seeping into the ground.
Question 5. Why do water droplets form on a cold bottle?
Answer
Due to condensation of water vapour from the air.
Question 6. In which case evaporation is faster-water in a bottle or water on a plate?
Answer
The water on a plate will evaporate faster as its area exposed to air is larger.
Question 7. What is condensation?
Answer
Condensation is when water vapour turns into liquid water.
Question 8. What is meant by the conservation of water?
Answer
Careful, economical and wise use of water and avoiding the wastage of water is called conservation of water.
Question 9. What is melting?
Answer
Melting is the transition from solid (ice) to liquid (water).
Question 10. What does an Atmospheric Water Generator do?
Answer
It produces drinkable water from humid air.
Question 11. What is condensation?
Answer
The process of conversion of water vapours into liquid form of water is called condensation. It is reverse process of evaporation.
Question 12. Why do clothes dry faster on windy days?
Answer
Wind increases the rate of evaporation.
Question 13. What factors affect evaporation?
Answer
Temperature, surface area, air movement, and humidity.
Question 14. How does evaporation cool us down?
Answer
Evaporation absorbs heat, cooling the surroundings.
Question 15. What role does condensation play in the water cycle?
Answer
It forms clouds and returns water to the Earth's surface.
Question 16. Why does water vapor rise in the atmosphere?
Answer
It is less dense than the surrounding air.
Question 17. What is the cooling effect of evaporation observed in?
Answer
Sweating and cooling of earthen pots.
Question 18. What happens to the shape of ice when it is placed in different containers?
Answer
Ice retains its shape irrespective of the container.
Question 19. What is freezing?
Answer
Freezing is the transition from liquid (water) to solid (ice).
Question 20. How do clouds form rain?
Answer
Through condensation of water vapour into droplets.
Question 21. Why is water essential for living things?
Answer
It is crucial for survival and maintaining health.
Short Answer Questions
Question 1. Why is ocean water not suitable for domestic use?
Answer
Sea and ocean water contain large amounts of various salts. It is due to these salts, the ocean water is salty and cannot be used for drinking, washing and for irrigation purposes.
Question 2. What is evaporation?
Answer
Evaporation is the process of conversion of water into its vapour state. It takes place continuously, even at room temperature.
Question 3. What causes the cooling effect in an earthen pot?
Answer
The cooling effect in an earthen pot is caused by water seeping through the surface of the pot and evaporating. This evaporation process imparts a cooling effect on the water inside the pot.
Question 4. What are the three states of water? Describe them briefly.
Answer
Water exists in three states: solid (ice), liquid (water), and gas (water vapour). Ice retains its shape, water takes the shape of its container, and water vapour spreads out in the entire available space.
Question 5. During winters why do we see more fog in close areas where there are lots of trees?
Answer
Due to lots of trees, air at that place contains much more water vapour during winters. These vapour condense on dust or smoke particles forming thick fog.
Question 6. Does evaporation take place in shade also? Give an experiment to support your answer.
Answer
Yes evaporation takes place in shade also. Keep a plate in shade. Put some water in it. We note that water disappears slowly from the plate. The water evaporates though very slowly from the plate because of atmospheric heat.
Question 7. What is condensation?
Answer
Condensation is the process of conversion of water vapour into its liquid state when it comes in contact with a cold surface, forming water droplets.
Question 8. Why is there a need for conserving water? Give two reasons.
Answer
The two reasons for the need for conserving water are:
- Increasing population needs more water.
- Availability of water is decreasing day-by-day.
Question 9. How does water change its state from solid to liquid and from liquid to gas?
Answer
Water changes its state from solid (ice) to liquid (water) when heat is supplied, and from liquid to gas (water vapour) on further heating.
Question 10. Why should we use groundwater judiciously?
Answer
If large quantity of groundwater is taken out for various purposes, the water level goes down. There will be lack of water in a few decades, if we continuously use water carelessly. So we should use groundwater very carefully.
Question 11. Why do clothes dry faster on a windy day?
Answer
Clothes dry faster on a windy day because the movement of air increases the rate of evaporation of water from the clothes.
Question 12. Give three examples of evaporation.
Answer
- Drying of wet clothes
- Drying of mopped floor
- Drying of sweat from our body.
Question 13. What causes the water droplets to appear on the outer surface of a cold glass tumbler?
Answer
The water droplets appear due to condensation, where water vapour in the air cools down and changes into liquid water on the cold surface.
Question 14. What is dew and how it is formed?
Answer
On a clear day, water evaporates from the warm ground into the atmosphere. When night falls, the ground radiates the day’s warmth into the sky. The ground becomes much cooler, causing the water vapour to condense. This condensed vapour is dew.
Long Answer Questions
Question 1. Distinguish between evaporation and condensation.
Answer
|
Evaporation |
Condensation |
|
1. This is a process of changing water from its liquid form to its vapour form. |
1. This is a process of conversion of water vapour into liquid form. |
|
2. It involves heating. |
2. It involves cooling. |
Question 2. What is meant by conservation of water? Suggest three methods to conserve water.
Answer
Careful and economical use of water and avoiding its wastage is called conservation of water.
Suggestions for conserving water:
- Use only the required quantity of water.
- Trees and forests help in causing rainfall. So to conserve water, we should plant more and more trees.
- By collecting rainwater in tanks, ponds or by constructing check dams.
Question 3. How does the water cycle work?
Answer
The water cycle works through a continuous process of evaporation, condensation, and precipitation. Here’s how it works:
- Evaporation: Water from the ocean, lake, and other water bodies evaporates into the atmosphere as water vapour.
- Condensation: The water vapour cools and condenses to form clouds.
- Precipitation: Water returns to the Earth's surface as rain, hail, or snow.
- Collection: The precipitation collects in rivers, and groundwater, and eventually flows back to the ocean, where the cycle begins again.
This circulation of water helps maintain the balance and availability of water on Earth.
Question 4. Mention the factors on which rate of evaporation depends and how?
Answer
Evaporation depends upon the following factors:
- Temperature
- Surface area of water
- Speed of air over the exposed surface of water
- Humidity Large surface area, high temperature and high speed of air increase the rate of evaporation.
Evaporation causes cooling effect. Lesser the humidity faster will be the evaporation.