1. Table of Contents The Properties of Water Water on Earth Surface Water
Wetland Environments
Water Underground

2. The Structure of Water - The Properties of Water
The positive hydrogen ends of one water molecule attract the negative oxygen ends of nearby water molecules. As a result, the water molecules tend to stick together.

3. Changing State - The Properties of Water
Ice is solid water, the familiar form of water is a liquid, and the water vapor in the air is a gas.

4. Changing State - The Properties of Water
Water moves between the liquid and gaseous states by evaporation and condensation. Water moves between the liquid and solid states by freezing and melting.

5. Building Vocabulary - The Properties of Water
A definition states the meaning of a word or phrase by telling about its most important feature or function. After you read the section, reread the paragraphs that contain definitions of Key Terms. Use the information you have learned to write a definition of each Key Term in your own words.
Key Terms:
Examples:
evaporation
condensation
Key Terms:
Examples:
solution
solvent
specific heat
Key Terms:
Examples:
polar molecule
A solution is a mixture that forms when one substance dissolves another.
A molecule that has electrically charged areas is a polar molecule.
Evaporation is the process by which molecules at the surface of a liquid absorb enough energy to change to the gaseous state.
capillary action
The combined force of attraction among water molecules and with the molecules of surrounding materials is called capillary action.
The substance that does the dissolving is called the solvent.
The process by which a gas changes to a liquid is called condensation.
surface tension
Surface tension is the tightness across the surface of water that is caused by the polar molecules pulling on one another.
Specific heat is the amount of heat needed to increase the temperature of a certain mass of a substance by 1ºC.

6. Links on Water Properties
- The Properties of Water
Links on Water Properties
Click the SciLinks button for links on water properties.

7. Click the Video button to watch a movie about universal solvent.
- The Properties of Water
Universal Solvent
Click the Video button to watch a movie about universal solvent.

8. Click the Video button to watch a movie about changing state.
- The Properties of Water
Changing State
Click the Video button to watch a movie about changing state.

9. End of Section: Properties of Water

10. Distribution of Earth’s Water
- Water on Earth
Distribution of Earth’s Water
Most of Earth’s water–roughly 97 percent–is salt water found in oceans.

11. Distribution of Earth’s Water
- Water on Earth
Distribution of Earth’s Water
Only three percent of Earth’s water is fresh water.

12. The Water Cycle - Water on Earth
In the water cycle, water moves from bodies of water, land, and living things on Earth’s surface to the atmosphere and back to Earth’s surface.

13. Water Cycle Activity - Water on Earth
Click the Active Art button to open a browser window and access Active Art about the water cycle.

14. Identifying Main Ideas
- Water on Earth
Identifying Main Ideas
As you read the section “Distribution of Earth’s Water,” write the main idea in a graphic organizer like the one below. Then write four supporting details that further explain the main idea.
Main Idea
Earth’s water is distributed among oceans, rivers and lakes, and groundwater.
Detail
Detail
Detail
Detail
Oceans in the form of salt water, in which 97 percent of Earth’s water is found.
Ice in the form of icebergs near the North Pole and South Pole
Rivers and lakes, which contain the smallest amount of fresh water on Earth.
Groundwater, which fills cracks and spaces in underground soil and rock layers.

15. End of Section: Water on Earth

16. River Systems - Surface Water
A river and all of its tributaries make up a river system.

17. River Systems - Surface Water
The land area that supplies water to a river system is called a watershed.

18. Ponds and Lakes - Surface Water
Ponds and lakes are bodies of still fresh water. Ponds often support a wide diversity of living things.

19. How Lakes Can Change - Surface Water
In addition to seasonal changes, a lake can undergo long-term changes that may eventually lead to its death. These long-term changes are called eutrophication.

20. Outlining - Surface Water
As you read, make an outline about this section. Use the red headings for the main ideas and the blue headings for the supporting ideas.
River Systems
Tributaries
Watersheds
Divides
Ponds and Lakes
Exploring a Pond
Exploring a Lake
Lake Formation
How Lakes Can Change
Seasons Changes
Long-Term Changes
Death of a Body of Fresh Water

21. Click the PHSchool.com button for an activity about surface water.
More on Surface Water
Click the PHSchool.com button for an activity about surface water.

22. End of Section: Surface Water

23. The Everglades: A Wetland
- Wetland Environmentss
The Everglades: A Wetland
Water is the key to the Everglades, a unique region of grassy wetlands. The Everglades is a shallow stream of water that moves slowly over the land from Lake Okeechobee south to Florida Bay.

24. The Everglades: A Wetland
- Wetland Environmentss
The Everglades: A Wetland
A rich variety of living things make their homes in the Everglades.

25. Asking Questions - Wetland Environmentss
Before you read, preview the red headings. In a graphic organizer like the one below, ask a what or how question for each heading. As you read, write answers to your questions.
Question
Answer
What are the types of wetlands?
The three types of wetlands are marshes, swamps, and bogs.
What is the Everglades?
The Everglades is a region of wetlands stretching from Lake Okeechobee south to Florida Bay.
How are wetlands important?
They provide habitats for many living things and have many functions useful to people.

26. Click the SciLinks button for links on wetlands.
- Wetland Environmentss
Links on Wetlands
Click the SciLinks button for links on wetlands.

27. End of Section: Wetland Environments

28. How Water Moves Underground
- Water Underground
How Water Moves Underground
Water underground trickles down between particles of soil and through cracks and spaces in layers of rock.

29. Uses of Water - Water Underground
The graph shows water use in the United States. Each category of water use is represented by a different wedge. Use the graph to answer the questions below.

30. Uses of Water - Water Underground Reading Graphs:
How many categories of water use are shown on the graph? 4

31. Uses of Water - Water Underground Interpreting Data:
The two largest categories of water use combine to make up what percentage of the total water used in the United States?
80.5%

32. Uses of Water - Water Underground Interpreting Data:
Which of the categories of water use shown in the graph represents the largest use of water in the United States? Which represents the smallest?
Agriculture; industries and mining

33. Uses of Water - Water Underground Predicting:
How would an increase in the amount of farming affect this graph?
The percentage for agriculture would increase, and the percentage for all the other uses would decrease.

34. Uses of Water - Water Underground Calculating:
If the total daily usage of water in the United States is 1,280 billion liters, about how many liters are used each day by power plants?
About 495 billion liters

35. Bringing Up Groundwater
- Water Underground
Bringing Up Groundwater
People can obtain groundwater from an aquifer by drilling a well below the water table. They may also obtain water through pressure by digging an artesian well or from a spring.

36. Bringing Up Groundwater
- Water Underground
Previewing Visuals
Before you read, preview Figure 22. Then write two questions you have about the diagram in a graphic organizer like the one below. As you read, answer your questions.
Bringing Up Groundwater
Q. What is an artesian well?
A. It is a well in which water rises because of pressure within an aquifer.
Q. Where does the water that supplies a well come from?
A. Underground water comes from precipitation that trickles down between particles of soil and through cracks and spaces in layers of rock.

37. Links on Water Underground
Click the SciLinks button for links on water underground.

38. End of Section: Water Underground

39. Graphic Organizer Water evaporates. Water condenses to form clouds.
Water runs off into the ocean.
Water condenses to form clouds.
Water falls to Earth’s surface as precipitation.

40. End of Section: Graphic Organizer