LESSON 6: the Liquid Part of the Earth

LESSON 6: THE LIQUID PART OF THE EARTH The Origin of Water in the Earth

Pg. 93 – This mass of water that forms part of the Earth’s surface is called the hydrosphere.

Pg. 95 – In its solid state (ice), water occupies more volume and has a lower density than in its liquid state.

Pg. 96 – The water cycle is designated as the collection of processes by means of which water circulates, describing a cyclic route from the atmosphere to the Earth’s surface and returning again to the atmosphere.

Processes that Take Part in the Water Cycle

Pg. 96 – The processes that take part in the water cycle are evaporation, transpiration, condensation, and precipitation.

Pg. 104 – The contamination of water is defined as the alteration of water’s natural quality, in part or completely because of human action, that makes it inappropriate for its destined use.

Activities

1) Explain briefly how the primitive oceans could have formed.

4) Where can we find water on the each in each one of its three states?

8) Why do you sweat more when you have a fever or feel hot?

11) The water cycle has an essential role in life on Earth. a. Define the water cycle. b. What changes in state take place during this cycle? c. What is the motor that activates the water cycle?

14) Elaborate a concept map with the following terms: hydrosphere, ground water, ocean water, lakes, seas, continental water, torrents, rivers, lagoons.

18) Why do we say that water intervenes in the formation of the landscape?

19) Explain how the following landscapes could have formed: meander, beach, delta, narrow pass.

21) What are continental waters? In what different form can we find them?

23) What are aquifers? How are they formed?

25) From where do we obtain drinking water? 26) What is a reservoir? Do you know of one? Cite it.

27) Do you think ground water is important? Why?

28) What is the difference between making water potable and purifying water?

29) What do you understand about contaminated water?

31) What is acid rain? What effects does it have?

33) What are the principal contaminants of seas and oceans?

34) What are black tides?

36) Investigate which communities in our country most are lacking in water. Do you think that the transfers that are occurring in some zones are a good solution?

Clear Ideas

 It is believed that a part of the Earth’s water comes from interstellar space and the other part comes from water vapour condensing from the cooling of our planet.

 The hydrosphere is the mass of water that forms part of the Earth’s surface and occupies 70% of it.

 97% of the water in the hydrosphere is salt water and 3 % is fresh water.

 The greatest part of fresh water is stored in the form of ice in the polar caps; only 0.01% of the percentage available to living beings serves to cover the necessities of human populations.

 Water is formed by a combination of the elements hydrogen and oxygen. Their chemical formula is H2O.

 Water is the largest component of living beings.

 The properties of water are the following: o It is a good dissolvent. o It heats and it cools more slowly than air or land. o It reaches its maximum density at 4° C, and because of this, ice floats in liquid water.

 The water cycle comprises the collection of processes by means of which water circulates, describing a cyclic route from the atmosphere to the Earth’s surface and returning again to the atmosphere.  The processes that take part in the water cycle are: evaporation, transpiration, condensation, and precipitation.

 The importance of the water cycle is rooted in the relation that it has as much with the climate as with landscape configuration.

 Fresh water is found in the continents in the form of glaciers, rivers and torrents, lakes, and subterranean water.

 Water destined for human consumption is obtained from rivers, reservoirs, and subterranean waters.

 Before consumption, water must be made potable in a potabilization plant.

 The contamination of water is the alteration of its natural quality, in part or completely because of human action, that makes it inappropriate for its destined use.