1. The Properties of Water

2. The structure of water
Each water molecule has two positive ends and one negative end. The positive ends of one water molecules are attracted to the negative end of another molecules. As a result, the water molecules tend to stick together.
A molecule that has electrically charged areas is a polar molecule.

3. Properties of water
The properties of water are capillary action ,surface tension, the ability to dissolve many substances and high specific heat.
Capillary action is the combined force of attraction among water molecules and with the molecules of surrounding materials. Example: water rises in the tube.

4. Properties of water
Surface tension is the tightness across the surface of water caused by the polar molecules pulling one another.The pulling forces the surface of the water into curved shape.
Universal Solvent: Many substances dissolve in water. A solution is a mixture that forms when one substance dissolves another.
The substance that does the dissolving is called a solvent. Water is a solvent.
Many substance dissolve in water because water is polar. The charged ends of the water molecule attract the molecules of the other polar molecules.

5. Properties of Water
Specific heat is the amount of heat needed to increase the temperature of a certain mass of a substance by 1°C.Water requires a lot of heat to increase its temperature.

6. Changes in the state of matter
Solid
Liquid
Gas

7. Information that you need to cover on your own for test #2
Distribution of water-Most of the Earth’s water-roughly 97% saltwater found in the ocean,3% is fresh water. Study figure 8 on page 15.
Water Cycle-study diagram on page 16 figure 9.
Uses of water-People use water for household purposes, industry, transportation, agriculture, and recreation. Read pages Give examples of each use.

8. Surface Water
The streams and smaller rivers that feed into the main river are called tributaries.
Tributaries flow downward toward the main river, pulled by the force of gravity. A river and all its tributaries together make up a river system.
Watersheds are the land areas that supplies water to a river system. Watersheds are sometimes known as drainage basins.

9. Surface Water Ponds and lakes are bodies of freshwater.
Ponds and lakes contain still or standing water.
In general, ponds are smaller and shallower than lakes.
Sunlight usually reaches at the bottom of the pond. Most lakes have areas where the water is too deep for sunlight to reach the bottom.
Ponds and lakes form when water collects in hollows and low lying area of land.

10. Surface Water
Lakes can undergo seasonal changes and a long term change that may eventually lead to its death.
Seasonal change are common in the northern areas of North America. In summer, warm water floats on op of the cooler ,denser, lower layer. But in the fall, the top layer of water cools off, too. As the top layer cools, it becomes denser and sinks. This causes the lake waters to mix. This mixing is called lake turnover.
Long-term change-This happens over a long period of time. The organisms in a lake constantly release waste products into the water. The waste and dead remains of dead organisms contain nutrients such as nitrates and phosphate. Algae feed on these nutrients. Over many years the nutrients build up in the lake in a process called eutrophication. Eutrophication causes more algae to grow, a thick ,green scum forms on the surface of the water.

11. Wetland Environments
A wetland is a land area that is covered with shallow layer of water during some or all of the year.
Wetlands help control floods and provide habitats for many species. They form in places where water is trapped in low areas or where groundwater seeps to the surface.
The 3 types of freshwater wetlands are marshes, swamps, and bogs.

12. Wetland Environments
Marshes are grassy areas covered by shallow water or a stream.
Swamps look more like flooded forests, with trees and shrubs sprouting from the water. Many swamps are located in warm, humid places.
Bogs are more common in cooler northern areas. They often form in depressions left by melting ice sheets thousands of years ago. The water bogs tends to be acidic, and mosses thrive in these condition.
Because of their sheltered waters and rich supply of nutrients, wetlands provide habitats for many living things.
In the before the 1970’s people thought wetlands were worthless, they drained the wetlands and placed farms, homes and businesses.
Scientific studies showed that wetlands serve important functions for people as well as for wildlife. For example, as water moves slowly through a wetland, some waste materials settle out. Other wastes may be absorbed by plants. Wetlands act as natural water filters. They also help control floods by absorbing extra run off from heavy rains. Wetlands are like giant sponges, storing water until it gradually drains or evaporates.

13. Water Underground Underground water comes from precipitation.
Recall that precipitation can evaporate, run off the surface, or soak into the ground.
If water soaks into the ground , it trickles downward, following the pull of gravity.
Water underground trickles down between particles of soil and through cracks and spaces in layers of rock.

14. Water Underground
Different types of rock and soil have different-sized spaces, or pores, between their particles.
The size of the pores determines how easily water moves through rock and soil.
Large and connected pores allow water to pass through or permeate. They are known as permeable materials.
Materials that have few or no pores or cracks are known as impermeable materials.
The area of permeable rock or soil that is totally filled, or saturated, with water is called the saturated zone.The top saturated zone is the water table.

15. Water Underground
Any underground layer of rock or sediment that holds water is called an aquifer.
Aquifers range in size from a small underground patch to an area of the size of several states.
Millions of people obtain there drinking water from this underground storehouse. It also provides water for crops and livestock.
People can obtain groundwater from an aquifer by drilling a well below the water table.

16. Information that you need to cover on your own for test #2
Water Conservation-Conservation is the practice of using less of a resource so that it will not be used up. Reducing water use, recycling water and reusing water are three ways to conserve. You must be able to give examples of water conservation. (Read pages 52-53)

17. Information that you need to cover on your own for test #2
Water pollution is the addition of any substances that has a negative effect on water or the living things that depend on the water.
The three major sources of water pollutions are human wastes, industrial wastes and chemical runoff. You must be able to give specific examples for each major source of pollution. (Read pages )