The water cycle.

The water cycle
Water moves from one part of the planet to another. it falls from the atmosphere down to the earth, rivers and seas.
It evaporates from the earth, rivers and lakes and goes back into the atmosphere.
This continual movement of water from one place to another is know as the water cycle. Living being also interve in the water cycle.
Example:
Trees more huge quantities of water. Theyabsorb water through their roots and then lose it it again through their leaves.
Why does water move?

• The movement of water from the rivers to the seas is due to the inclination the land. The movement of water from glaciers and the sow from from the mountains to the rivers is due to melting.
• The movement of from seas, and lakes to the atmosphere is due to evaporation.
• Water vapour cools in the atmosphere and forms drops of water.This is condensation.

Water is not evenly spread out

The propierties of water

Water properties

Before we begin looking at the properties of water, maybe you'd like to take our True/False quiz about water properties. Some of the answers may surprise you.

What are the physical and chemical properties of water that make it so unique and necessary for living things? When you look at water, taste and smell it - well, what could be more boring? Pure water is virtually colorless and has no taste or smell. But the hidden qualities of water make it a most interesting subject.

the water have 3 states

solid: for example, ice

Water pollution: is the contamination of water bodies such as lakes, rivers, oceans, and groundwater. All water pollution affects organisms and plants that live in these water bodies and in almost all cases the effect is damaging either to individual species and populations but also to the natural biological communitis. It occurs when pollutans are discharged directly or indirectly into water bodies. without adequate treatment to remove harmful constituents.

Industrial waste is a type of waste produced by industrial activity, such as that of factories, mills and mines. It has existed since the outset of the industrial revolution.

Much industrial waste is neither hazardous nor toxic, such as waste fiber produced by agriculture and logging.

Toxic waste and chemical waste are two designations of industrial waste.

Sewage treatment can be used to clean water tainted with industrial waste.

OIL SLICKS

Oil slicks float on oceans and seas, covering them in a thick film of crude or refined petroleum oil. When freight ships carrying tens of thousands of tons of fuel crash, malfunction, or encounter harsh weather, they spill enormous amounts of oil into the water. Since oil and water don't mix, the oil spreads out into a layer that hovers, as one mass, on top of the ocean.

martes 4 de agosto de 2009
how aquatic creatures adapt
many organisms live in a water medium. these creatures are well-adapted for moving and breathing in water.

- aquatic plants and weeds have flexible steams which do not break when they are moved by the current. they don need strong stems like plants on land because the water support them.

-aquatic animals usually have a streamlined shape like, for example a fish so that they can overcome the resistance of water. their extremities are usually wide like oars.

BREATHING IN WATER

aquatic plants and animals obtain their oxygen from the oxygen dissolved in water.

-aquatic plants breathe thought their leaves like plants like plants on land.

-aquatic animals have different organs for obtain oxygen from water. fish for example, have organs called gills which they use for breathing. gills are made up of small filaments which take in oxygen and expel carbon dioxide. this system.