Water

We would not be able to cook food, clean utensils, bath, wash cloth, clean floor, toilet works, brushing, and most important drinking.

We need water for so many activities like cook food, clean utensils, bath, wash cloth, clean floor, toilet works, brushing, and most important drinking.

We obtain food from plants, plants needs water to grow and cook their food by the process of photosynthesis. Water is used in industries for processing large number of things that we uses like fabrics, paper etc,

We get water from water bodies like river, spring, pond, well and hand pump. Although the rain water is the natural source of water that fulfil various water bodies.

Water in ocean and seas are salty because,many salts are dissolved in it, so it is unfit for drinking.

Water spilled on floor dries up after sometimes because of the process of evapaoration.

Evaporation takes place in presence of sunlight, that heats up the open water surface and convert it into water vapour.

The process of loss of water from the aerial part of plants like leaves is called transpiration.

The water vapours present in sky are gas and cannot be seen. When air is cooled for some reason, each water vapour gather and tie with neighbouring water vapour. Thus vapor forms many water drops, each of which consists of many water molecules. One drop is very small and can float in the air. (But when a drop is large enough they begin to fall as rain.) It cannot be seen but when very large number of drops gathers they are visible like fog or smoke. This is cloud. There are many chances when cloud is formed. For example towering thundercloud is formed when air rises high up in the sky.

Rain cloud is dark because their water drops are larger and less transparent

On a clear day, water evaporates from the warm ground into the atmosphere. When night falls, the ground radiates the day's warmth into the skies. The ground becomes much cooler, causing the water vapour to condense. This condensed vapour is dew.

Some of the water flows in the form of rivers and streams, the rain water also fills up the lakes and pond, a part of rain water gets absorbed by the ground and seems to disappear in the soil. Some of this water is brought back to the air by the process of evaporation and transpiration.

Ground water is the water located beneath the earth's surface in soil and in the fractures of rock formations.

The Water Cycle is the journey of water from the land to the sky and back again. There are six important processes that make up the water cycle.

1. Condensation - the opposite of evaporation. Condensation occurs when a gas is changed into a liquid.
2. Infiltration - Infiltration is an important process where rain water soaks into the ground, through the soil and underlying rock layers.
3. Runoff - Much of the water that returns to Earth as precipitation runs off the surface of the land, and flows down hill into streams, rivers, ponds and lakes.
4. Evaporation - the process where a liquid, in this case water, changes from its liquid state to a gaseous state.
5. Precipitation - When the temperature and atmospheric pressure are right, the small droplets of water in clouds form larger droplets and precipitation occurs. The raindrops fall to Earth.
6. Transpiration - As plants absorb water from the soil, the water moves from the roots through the stems to the leaves. Once the water reaches the leaves, some of it evaporates from the leaves, adding to the amount of water vapour in the air. This process of evaporation through plant leaves is called transpiration.

Excess of rainfall leads to many problems. It raises the water level in rivers, lakes and ponds. The water may then spread over larger area causing the situation of floods. The crop fields, forests, villages and cities may get submerged by water.

If it does not rain for a longer period of time then the water level in rivers, lakes and ponds will go down, some of them may even dry up. The ground water also becomes scarce. This may lead to draught.

By making wise and judicious use of available water, we can save water. We should not waste water and try to harvest rain water.

Roof top rain water harvesting- in this system rain water is collected from roof top to a storage tank through pipes. There is one more method in which rain water is allowed to go into the ground directly from the road side drains that collect rain water.

If it does not rain for a longer period of time then the water level in rivers, lakes and ponds will go down, some of them may even dry up. The ground water also becomes scarce. This may lead to draught.

The most air coming out from mouth condenses on glasses to make glasses wet.

The cool surface of cooled bottle cools the air around it and the water vapours of the air condenses on the surface of the bottle