WATER IS LIFE

4. Answer the following:

a. Enlist five uses of water

Ans - Water is used for irrigation.

-Water  is used in various industries like paper, chemical, fertiliser, textile and pharmaceuticals.

-Water is used by animals for digestion, absorption, excretion, regulate body temperature etc.

-Water is used for transport.

-Water is used for recreation.

b. Explain the importance of conservation of water

Ans -  As only 0.3% of fresh water is available for our use we should not waste and pollute water. We need to find innovative ways to reuse water for more than one purpose.

c. Name the different processes involved in a water cycle.

Ans-  Evaporation, transpiration, condensation and precipitation

d. Explain the role of transpiration in a water cycle.

Ans - The evaporation of water from the leaves of a plant is known as transpiration which accounts for 10% of total water vapour present in the air.

5. Define:

a. Ground water - Some of the rain water that falls soaks into the ground and stays there. this water absorbed in the ground is known as ground water.

b. Drought - It is a situation when a region receives below-average precipitation, resulting in prolonged shortages in its water supply, whether atmospheric, surface or ground water.

c. Evaporation - It is the process of conversion of water form rivers, lakes, streams, wetland and oceans into water vapour because of sunlight 

d. Water pollution - it is the contamination of water due to industrial and domestic waste products.

6. Answer in detail:

a. Explain the importance and the process of rain water harvesting

Ans - Rain water harvesting is the technique to collect rain water and store it for future use. Rain water can be collected on rooftops. This water can be directed with pipes into water storage tanks or pits in low- lying areas to collect rain water. rain water can be collected in shallow trenches to enhance the absorption  of water into the soil. the harvested water can be filtered, disinfected and then used.

b. Describe the different sources of water.

Ans - 97% of the Earth’s water is in the oceans(saline water) which is not suitable for drinking, domestic or industrial use. The remaining 3% of water is fresh water. Out of this tiny fraction, almost 70% of water is frozen in ice caps or glaciers. The remaining 30% of the fresh water is found  as ground water,rain water and surface water. Surface water which is readily available for our use is only 0.3% of total fresh water. this includes water of rivers, lakes, ponds and streams.

c. Describe the different events in a water cycle.

Ans - Water cycle( Hydrologic cycle)  is the continuous movement of water from the atmosphere to the Earth and back to the atmosphere. different events of water cycle are:

1) Evaporation - It is the process of conversion of water form rivers, lakes, streams, wetland and oceans into water vapour because of sunlight.

2) Transpiration -The evaporation of water from the leaves of a plant is known as transpiration which accounts for 10% of total water vapour present in the air.

Hot air become lighter which carries water vapour high up in the sky. 

3) Condensation - The vapour starts condensing into water on the surface of dust particles present in the air due to reduced temperature. The clusters of water droplets in the air are visible as clouds.

4) Precipitation - The water droplets from clouds become bigger and heavier, they fall down on the Earth as rain, hail and snow. this process is known as precipitation.

7.

a. Why do many vegetables get reduced in quantity when cooked?

Ans - Most of the vegetable contains water in good amount which get evaporated while cooking. This will lead to reduction in quantity of vegetable after cooking.