3rd Grade ICSE

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Prepared by: learnloophq@gmail.com

Last edited 37 days ago by Learn LoopHQ.

Chapter: 09. Water As A Resource

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Section A: Multiple Choice Questions

c) Plasma

c) Evaporation

d) Sand

c) Cholera

b) 71 percent

Section B: Fill in the Blanks

universal

clouds

water cycle

Waterworks

chlorination

Section C: True or False

False

True

False

Section D: Short Answer Questions

We use water for drinking and washing clothes in our daily lives. (Other acceptable answers: cleaning, cooking, bathing, etc.)

Germs are very tiny, harmful living organisms that cannot be seen with the naked eye. They are dangerous in drinking water because they can cause various diseases and make people fall ill.

It is important to conserve water because freshwater is a limited resource on Earth, and we cannot live without it for survival and daily activities. (Other acceptable reasons: prevent water scarcity, reduce energy/cost for purification, protect ecosystems.)

The easiest method to purify water at home to kill germs is boiling it for at least 10 minutes.

Section E: Diagram-Based Question

During precipitation, the water droplets in the clouds become very heavy and fall back down to the Earth’s surface in the form of rain or snow. This is how water returns from the sky to the land and water bodies.

The Sun is the source of energy that causes “evaporation” in the water cycle. The Sun’s warmth heats the water in oceans, lakes, and rivers, causing it to turn into water vapour and rise into the atmosphere.

Section F: Identify and Differentiate

Differentiate between Evaporation and Condensation.

Evaporation: This is the process where liquid water changes into water vapour (a gas) when it is heated.

Condensation: This is the process where water vapour (a gas) changes back into liquid water droplets when it cools down.

Differentiate between Insoluble Impurities and Soluble Impurities.

Insoluble Impurities: These are substances that do not dissolve in water and can be easily seen, such as sand or mud.

Soluble Impurities: These are substances that dissolve completely in water and therefore cannot be easily seen, such as salt.

Section G: Long Answer Question

Three different methods you can use to purify water at home to make it safe for drinking are:

Boiling: This is the easiest and most effective method. You should boil water for at least 10 minutes, as the high heat effectively kills most harmful germs present in the water.

Filtering: You can use a water filter (like a home water filter or even a clean cloth) to remove insoluble impurities such as dirt, sand, and other visible particles. This makes the water look cleaner.

Chlorination: You can add chlorine tablets to the water. These tablets release chlorine, which is a chemical that kills various germs that can cause waterborne diseases like cholera and jaundice, making the water safe to drink.

Section H: Observation-Based Question

The tiny water droplets formed on the outer surface of the cold glass due to condensation. Your refrigerator glass is very cold, and the air around it contains invisible water vapour. When this warmer water vapour in the air touches the cold surface of the glass, it quickly cools down. As it cools, the water vapour changes from a gas back into tiny liquid water droplets, which then become visible on the outside of the glass.

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