Worksheets With Solutions: Water: A Precious Resource Class 7 Worksheet Science

Section A: Multiple Choice Questions

Correct Answer is Option (d)
Solid water refers to ice, liquid water is the form we commonly drink and use, and gaseous water is water vapor in the atmosphere.

Q.2. What is the process of water changing from a liquid to a gas?
(a) Melting
(b) Condensation
(c) Evaporation
(d) Freezing

Correct Answer is Option (c)
This is the process in which liquid water changes into water vapor, which then rises into the atmosphere. 

Q.3. What is the term used for the continuous movement of water between the earth and the atmosphere?
(a) Water distribution
(b) Water cycle
(c) Water recycling
(d) Water conservation

Correct Answer is Option (b)
This refers to the continuous movement of water between the earth's surface and the atmosphere, involving processes such as evaporation, condensation, and precipitation.

Q.4. What is the primary source of water for agriculture?
(a) Surface water
(b) Underground water
(c) Rainwater
(d) Sea water

Correct Answer is Option (d)
This is the primary source of water for irrigation in many parts of the world, where water is extracted from wells and aquifers.

Q.5. Which of the following is not a method of conserving water?
(a) Rainwater harvesting
(b) Recycling of water
(c) Fixing leaks and dripping taps
(d) Wasting water

Correct Answer is Option (d)
Conserving water refers to using water efficiently and reducing wastage. Rainwater harvesting, recycling of water, and fixing leaks and dripping taps are all methods of conserving water.

Section B: Short Questions

The main difference between solid water (ice) and liquid water is their physical state. Solid water is in a solid state with a fixed shape and volume, while liquid water is in a liquid state that takes the shape of its container and has a fixed volume.

Q.2. Explain the process of water changing from a gas to a liquid.

The process of water changing from a gas to a liquid is called condensation. This occurs when water vapor cools down and loses energy, causing its molecules to slow down and come closer together. As a result, the water vapor converts back into liquid form, forming droplets that can be seen on surfaces such as windows or grass.

Q.3. What are the sources of water?

The sources of water include natural sources such as rain, rivers, lakes, and groundwater, as well as man-made sources such as desalination plants and recycled wastewater.

Q.4. What is the significance of dams in water conservation?

Dams play a significant role in water conservation by helping to regulate water flow and store water for future use. They also provide hydroelectric power and can help prevent floods by controlling the release of water downstream.

Q.5. What are the consequences of water scarcity on plants?

Water scarcity can have severe consequences on plant life. Lack of water can cause plants to wilt, reduce their growth rate, and even lead to their death. Additionally, water scarcity can affect the quality of soil, making it more difficult for plants to absorb nutrients and grow properly.

Section C: Fill in the blanks

Evaporation is the process by which water changes from a liquid to a gas.
Evaporation is the process where water molecules gain energy and transform from a liquid state to a gas state, rising into the atmosphere.

Q.2. The three forms of water are ___________ water, ___________ water, and ___________ water.

The three forms of water are liquid water, solid water, and gaseous water.
Water can exist in three states, liquid water (for example, rivers, lakes, oceans), solid water (such as ice and snow), and gaseous water (such as water vapor in the air).

Q.3. The ___________ is the continuous movement of water from the Earth's surface to the atmosphere and back again.

The water cycle is the continuous movement of water from the Earth's surface to the atmosphere and back again.
The water cycle is the process by which water evaporates from oceans, rivers, lakes, and other bodies of water, rises into the atmosphere as water vapor, forms clouds, and then falls back to Earth as precipitation.

Q.4. The two major sources of water are ___________ water and ___________ water.

The two major sources of water are surface water and ground water.
Surface water refers to water that is found on the surface of the Earth in rivers, lakes, oceans, and other bodies of water. Groundwater is water that is found beneath the surface of the Earth in spaces between rocks and soil.

Q.5. ___________ is the process of collecting and storing rainwater for later use.

Rainwater harvesting is the process of collecting and storing rainwater for later use.
Rainwater harvesting involves collecting rainwater from rooftops, gutters, and other surfaces and storing it for later use in watering plants, washing clothes, and other non-potable uses. It can also be treated for potable use.

Section D: Match the column

1. Solid water - c. Frozen water
Solid water refers to water that is in a frozen state, such as ice or snow.
2. Liquid water - a. Water found in lakes and rivers
Liquid water refers to water that is in its liquid state, such as in lakes and rivers.
3. Gaseous water - b. Water found in the atmosphere
Gaseous water refers to water vapor that is present in the air and atmosphere.
4. Surface water - a. Water found in lakes and rivers
Surface water refers to water that is found on the surface of the Earth, such as in lakes and rivers.
5. Underground water - d. Water found in underground aquifers
Underground water refers to water that is located beneath the Earth's surface, often in underground aquifers or other underground water sources.

Section E: True or False

True - The water cycle is the continuous movement of water from the Earth's surface to the atmosphere and back again, through processes like evaporation, condensation, precipitation, and runoff.

Q.2. Dams are artificial barriers built across rivers to store water.

True - Dams are artificial barriers built across rivers to store water, which can be used for various purposes like irrigation, hydroelectric power generation, and drinking water supply.

Q.3. Groundwater is the water that flows over the Earth's surface.

False - Groundwater is the water that is stored beneath the Earth's surface, in underground aquifers and water tables. It is replenished through the infiltration of rainwater and other surface water.

Q.4. Water scarcity has no effect on plants.

False - Water scarcity can have significant effects on plants, as they need water to survive and grow. Lack of water can cause plants to wilt, dry up, and eventually die.

Q.5. Recycling of water is the process of collecting and storing rainwater for later use.

False - Recycling of water is the process of treating and reusing wastewater, so that it can be used for various purposes like irrigation, industrial processes, and even drinking water supply in some cases. Collecting and storing rainwater is known as rainwater harvesting.