Water

Water is considered one of the most necessary nutrient in our life, the people cannot survive without it. All the living beings should drink to survive. Drinking is healthy.

Humans use water to drink, to cook, to wash clothes Plants need water to live, without water the plants die Animals need water to live, some live in water and on land but the water is required for all of them Industrial use water: to manufacture, to prepare food, to generate electricity, etc.

Agricultural use: to irrigate the fields.

Aquaculture use water: to raise fish and other species.

Municipalities use water for irrigation of parks and gardens.

The states of water The water may appear in three different states: solid, liquid and gas Pax.1

Fresh water is a renewable resource, bat it is steadily decreasing. Awareness of the global importance of preserving water for ecosystem services increases each day. Without water, there's no life. So, we must be conscious of the importance to make a good use of it.

Since the start of the industrial revolution, man have not cared very much about contaminate the rivers, seas and aquifers. As the water is an important element in our lives it has become a reason of conflicts among farmers, industrialists, the tourism industry and even entire countries.

In Spain, the agriculture consumes 80% of the available drinking water . This supposes a waste of water, that could be infinitely smaller if instead of swamping the land, we employed other methods such as the leak-system. In countries like Israel, they have obtained important achievements with the leak-irrigation-system.

The urban provision is the second sector for consumption of drinking water. There are communities with an enormous waste of this prized liquid. The irrigation of public parks, private gardens, golf courses and the cleaning of the streets, carried out in its greater part with drinking is also a reason of conflicts.

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The water may appear in three different states: solid, liquid and gas The water we drink is a liquid The water in the freezer cubes is solid water The steam coming out of a pot is gaseous water

Changes in water status

The water state changes occur when water passes from one state to another and are as follows: When ice melts the water goes from solid to liquid. This change is called melting.

The water we put in the fridge to get ice cubes that change is called solidification.

When water is evaporated by the heat effect of this change is called evaporation.

When water vapor cools, it forms water, this change is called condensation . Condensed water that falls to the Earth is called precipitation (rain, snow, fog drip..)

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Most of the animals that live in the water are fish.

Some mammals like dolphins, whales and seals live in water The sea turtle and other reptiles live in water.

A lof amphibians like the frog live in water A lot of shellfish also live in water

Fish Fish are cold blooded.

They lay eggs.

Most fish are covered with scales.

They have fins not legs.

Fish breathe through gills and live in water.

How a fish breaths The fish takes water into its mouth. The water goes back through the gills. Then the gill cover at the side of the fish's head opens and the water runs out. This intake of water gives the fish oxygen. Out of the water a fish will die because the gills only work when the fish is in the water.

Fish that live in sea Anchovy, hake, cod, sardine, sea bass, sea bream, bream, ray, conger eel, monkfish; mackerel Fish that live in rivers Salmon, trout, eel Shell- fish Prawn, scallop, barnacle, shrimp, clam, loved, crab, musssel

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