WATER
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WATER
Water on our planet. Composition of water. Processes in which water intervenes. Localisation. Density of water. Ice. Water and life in deserts and jungles. Water and man: human-beings, Industry. Summary.
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INTRODUCTION
- Water is not an abundant substance in the universe.
- On our planet, water occupies approximately 70% of the earth’s surface. Water accounts for between 70 and 90% of the weight of living organisms.
- How did water appear on our planet?
WATER
- Composition of water
- Main characteristics of water.
- Plants’ photosynthesis. Water intervenes in many biological processes.
- Water as gas (clouds) and in solid state (ice).
- Water weighs less in its solid state than in its liquid one.
- Water and climate
- Polar seas: regulate the temperatures.
WATER AND LIFE
- Life appeared for the first time and developed in the seas.
- Water provided the necessary protection against solar radiation.
- When life left the water and started to occupy the land, water was still needed. Rains wet the ground, creating rivers and lakes.
- Tropical forests
- Intensely cold or very dry areas. Deserts.
- The Earth provides moisture for itself with rain and this, in turn, depends upon factors such as climate and wind.
WATER AND MAN
- Mankind needs more and more water for itself. Industrial activity. Dams and reservoirs. Electricity.
- Care of the environment. Filters and purifying-plants.
SUMMARY |
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