Class 6 Notes-Water
Short Answer Type Questions
1. List any four ways in which water can be conserved.
2. How are clouds formed?
3. What happens to plants when they are not watered?
4. Explain what you mean by evaporation.
5. What is the difference between fog and clouds?
6. What happens when there is a lot of rainfall?
7. Differentiate between the terms ‘evaporation’ and condensation’.
Ans:
1. The various ways to conserve or minimise the wastage of water are as follows:
(i) We should make economical use of water while taking a bath or washing clothes.
(ii) We should use drip irrigation or spray irrigation systems for our crops.
(iii) Do not use a full flush from the cistern on a toilet when a half flush is sufficient
(iv) Integrated watershed plans for drinking, irrigation and industrial areas should be
developed.
2. When the air moves up, it gets cooler and cooler and after reaching sufficient heights, the air becomes so cool that the water vapour present in it condenses to form tiny drops of water called droplets which remain floating in the air and thus clouds are formed.
3. If plants are not watered, they would wither. The seeds would not germinate and plants would not grow well.
4. The process of changing water (liquid form) into water vapour (gaseous form) is called evaporation
5. Clouds can form at many different altitudes. They can be as high as 12 miles above sea level or as low as the ground. Fog is a kind of cloud that touches the ground. Fog forms when the air near the ground cools enough
to turn its water vapour into liquid water or ice.
6. When it rains excessively, water gets collected here and there, causing disruption of normal life. The water levels of rivers, lakes and ponds rise. When it exceeds a certain maximum level, the water reservoirs cause floods. Crops, fields, villages and low-lying, areas get submerged under water. During floods, many animals living in water get trapped on land and die when the flood water recedes. Heavy rains also kill the animals living in soil because such animals do not get air to breathe when all the soil gets covered with flood water.
7. The process of changing water (liquid form) into water vapour (gaseous form) is called evaporation. This is the reason our perspiration dries up at room temperature and wet clothes dry up even in shade. However, if you heat water, it starts boiling at 100°C and rapidly changes to steam. If you cool steam, it changes to liquid water at
100°C. The process is called condensation.
Long Answer Type Questions
1. What is a water cycle? Describe the water cycle in nature. Also, draw a labelled sketch to show the water
cycle in nature.
2. Why is natural water not considered safe for drinking?
3. Discuss why water is required by plants and animals.
Ans:
1. Water keeps on circulating in nature.Although we use water for different activities, the amount of water remains the same on the earth’s crust. This is maintained by the water cycle. The cyclic pattern in which water keeps moving from the oceans and seas to the sky as water vapour, from the sky to the land as rain or snow and from land to the oceans and seas is known as the water cycle.
2. Oceans are the largest reservoirs of natural water because streams and rivers flow into them. The water in an ocean is saline in nature because there are various types of salts dissolved in it. Sea and ocean water cannot be used for drinking, washing clothes and for irrigation purposes due to the various salts dissolved in it.
Water in rivers becomes polluted due to human activities and is thus not considered safe for drinking.
3. Plants and animals mostly contain water in their body. They need a large amount of water for growth. Water is very important for life. Humans too need water to drink, to wash our hands, to cook, to water plants and for
many other things. Without water, the plants would die and people and animals would go thirsty.
Water provides habitat to many animals and plants. All animals and plants living in water are adapted to live in water.
HOTS
1. Water gets absorbed easily in the soil as compared to a cemented floor. Why?
2. Name a continuous process taking place in nature which involves all the following process
(which are not given in sequence): transpiration, evaporation, condensation
3. What happens to the potted trees when they are over watered? Why?
4. What would have been the consequence if the water was not recycled in nature by the water cycle?
Ans:
1. Water gets absorbed easily in the soil as compared to a cemented floor because the soil is porous in nature.
2. Water cycle
3. Waterlogging takes place and roots are unable to take oxygen from the soil.
4. There would be no water available for use. Most of the natural phenomenon would be affected.