NCERT Class 6 Science Chapter 8 A Journey through States of Water Important Extra Questions and Answers

Very Short Answer Type Questions

Question 1.
How does water in a puddle eventually disappear?
Answer:
Water in a puddle eventually disappears due to evaporation, where it turns into water vapour and rises into the air.

Question 2.
What happens to water when it freezes?
Answer:
When water freezes, it changes from a liquid state to a solid state, forming ice.

Question 3.
What is the process called when ice turns into water?
Answer:
The process is called melting.

Short Answer Type Questions

Question 1.
Explain how surface area affects the rate of evaporation.
Answer:
A larger surface area speeds up evaporation because more water is exposed to air, allowing more molecules to escape into the vapour phase.

Question 2.
Describe the process of condensation with an example.
Answer:
Condensation is the process where water vapour in the air cools and turns into liquid water. An example is dew forming on grass in the morning when the air cools overnight.

Question 3.
What role does temperature play in the process of evaporation?
Answer:
Temperature plays a crucial role in evaporation by providing energy to water molecules. Higher temperatures increase the rate of evaporation as more molecules gain enough energy to escape the liquid phase and turn into vapour.

Long Answer Type Questions

Question 1.
Explain the water cycle, including evaporation, condensation and precipitation.
Answer:
The water cycle is a continuous process that describes the movement of water within the Earth’s atmosphere and surface. It involves several key processes:

• Evaporation: Water from oceans, rivers, lakes and other bodies of water absorbs heat from the sun and transforms into water vapour.
• Condensation: As the water vapour rises, it cools and condenses into tiny droplets to form clouds.
• Precipitation: When the water droplets in clouds combine and grow larger, they eventually fall back to the Earth’s surface as precipitation.
• Collection: The precipitation collects in bodies of water such as rivers, lakes and oceans or infiltrates into the ground to recharge groundwater supplies.

Question 2.
Describe an experiment to demonstrate the process of evaporation and its effect on cooling.
Answer:
To demonstrate the process of evaporation and its cooling effect, you can conduct a simple experiment using two containers of water. Here’s a step-by-step guide:
Materials Needed:

• Two identical shallow containers or dishes
• Water
• A small fan (optional)
• A thermometer
• A piece of cardboard or paper
• A timer or stopwatch

Set Up the Experiment:

• Container A (Evaporation Setup): Place a piece of cardboard or paper on the surface of the water to cover it partially. This will reduce direct evaporation but not entirely stop it.
• Container B (Control Setup): Leave this container open to the air without covering it.

Simulate Evaporation:

• Fan option: If using a fan, position it to blow air across the surface of container B. This will increase the rate of evaporation in this container.
• Without fan: Simply leave both containers in the same environment without additional airflow:

Observe and Record:

• After a set period (e.g., 30 minutes), measure and record the temperature of the water in both containers again.

Analysis:

• Compare the temperatures of the water in container A and container B.
• Container A (Covered/Reduced Evaporation): Should show a slight decrease in temperature, but not as much as container B.
• Container B (Open/Enhanced Evaporation): Should show a more noticeable decrease in temperature due to increased evaporation.

Investigating Water’s Disappearing ACT Class 6 Extra Questions

Question 1.
After rain water puddles appear in the playground. After some time these disappear. Where does the water go?
Answer:
Water gets absorbed by the soil on the playground. It also evaporates.

Question 2.
After washing the utensils, water remains on the surface of utensils. After sometime it dries. Where does the water disappear?
Answer:
Water from the surface of utensils evaporates with time.

Question 3.
Do you heat the pan to observe evaporation?
Answer:
No. Evaporation takes place at room temperature also.

Question 4.
Give three examples of evaporation.
Answer:

1. Drying of wet clothes
2. Drying of mopped floor
3. Drying of sweat from our body.

Question 5.
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 6.
While making dosa, we sprinkle some water on the hot pan. Soon it disappears. Where does it go?
Answer:
It converts into steam.

Nother Mystery Class 6 Extra Questions

Question 1.
Take a tumbler with cold water. Keep it for some time. What do you observe?
Answer:
Some water droplets appear on the outer surface which become bigger with time due to condensation.

Question 2.
Suggest possible reasons explaining’the appearance of water droplets on the outer surface of the glass tumbler containing lemonade.
Answer:
Water does not come out from the glass tumbler. Water in the air deposits on the outer surface of the glass tumbler. This is due to condensation.

Question 3.
Give another example of condensation similar to water droplets on the outside tumbler containing cold water.
Answer:
Appearance of dew drops on the plants in the morning.

What are the Different States of Water Class 6 Extra Questions

Question 1.
Name a substance that can be observed in three different states.
Answer:
Water

Question 2.
How do you get three states of water?
Answer:
Take some ice. Heat it. It melts and gets converted into water. On further heating water gets converted into its gaseous state, i.e., vapours.

Question 3.
Compare the properties of ice, liquid water and water vapour.
Answer:
The shape and volume of ice does not change when shifted from one container to another. In case of water, shape depends on the container but volume remains the same. In case of water vapour, both shape and volume change. It occupies all available space.

Property	lee (solid state)	Water (liquid state)	Water vapour(gaseous state)
1. Ability to flow	No	Yes	Yes
2. Ability to spread	No	Yes	Yes

Question 4.
State some examples where three states are exhibited.
Answer:
Wax, oil and ghee.

 

Question 5.
Give example of four gases which spread if left-open.
Answer:
Smell of yummy food from cooking, oxygen, carbon dioxide and LPG (Liquefied petroleum gas). Oxygen and carbon dioxide do not smell and are not noticeable.

How can We Change the States of Water Class 6 Extra Questions

Question 1.
What is melting?
Answer:
The process of conversion of a solid into liquid is called melting.

Question 2.
What is freezing?
Answer:
The process of conversion of liquid into solid state is called freezing.

Question 3.
How can you change ice to liquid state and then to vapour?
Answer:
By supplying heat slowly and continuously we can change ice to liquid ~ water and then to vapour.

Question 4.
How do you change water to ice?
Answer:
By placing water in a cold environment such as freezer.

 

Question 5.
Name two examples other than water where you observe liquid to solid change and vice versa.
Answer:
Wax and coconut oil.

Question 6.
What is atmospheric water v generator (AWG)?
Answer:
This machine collects water from humid air and gives drinking water through the process of condensation.

How can Water be Evaporated Faster or Slower Class 6 Extra Questions

Question 1.
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 2.
Why do wet clothes placed on a clothes line get dry after some time? Explain.
Answer:
Wet clothes placed on a clothes line get dry after some time because water present in wet clothes is converted into water vapour due to evaporation and leaves them dry.

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.
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.
Why is there a need for conserving water? Give two reasons.
Answer:
The two reasons for the need for conserving water are:

1. Increasing population needs more water.
2. Availability of water is decreasing day-by-day.

Cooling Effect Class 6 Extra Questions

Question 1.
Which of the two- water in earthen pot or water in stainless steel pot will give cold water after being left for some time? Illustrate with another example.
Answer:
Water in the earthen pot will be cold. It is because water from the surface of the earthen pot evaporates and imparts a cooling effect on water. On the other hand, water in stainless steel will not give cold water.
Another Example: We cool the surface of the roof or floor by sprinkling water over it. Surahi is also used for similar purpose.

How do Clouds give us Rain Class 6 Extra Questions

Question 1.
Name the process which helps to bring evaporated water back to the earth’s surface.
Answer:
Condensation.

Question 2.
How does condensation help to form clouds? What causes rain?
Answer:
When air moves higher above the earth’s surface, it becomes cooler and cooler. At certain heights, the cooled vapour turns into droplets. When these droplets surrounded the dust particles, it forms clouds. When these cloudy droplets join together, it starts rain because drops are quite heavy and start falling.

 

Question 3.
What is water cycle?
Answer:
The water from the ocean and Earth’s surface evaporates into the atmosphere as vapour. In due course of time it forms heavy clouds of water and dust droplets due to condensation. This then falls as rain, hail or snow, ultimately flowing to the oceans. This cycle of water is called water cycle.

Question 4.
Name the natural processes leading to water cycle.
Answer:
Evaporation and condensation.