The Water of the Earth

Objectives:

• Students will be able to distinguish between salt water and fresh water.

• Students will be able to describe resources obtained from salt water.

• Students will be able to identify sources of fresh water.

• Students will be able to describe the water cycle.

Suggested Grades:

4rd Grade - 5th Grade - 6th Grade

Lesson Procedure:

Print the reading comprehension passage and questions (see below).

Students should read the passage silently, then answer the questions. Teachers may also use the text as part of a classroom lesson plan.

Lesson Excerpt:

There are two types of water on Earth â€" fresh water and salt water. More than 97 percent of the water on earth is salt water. This includes oceans, salt water lakes and inland seas. The salt in salt water is mostly from a rock salt known as halite. While humans cannot drink salt water for survival, the salt water environment is important for a number of reasons. It is rich in minerals and contains dissolved gases, oxygen and carbon dioxide. These characteristics make salt water excellent for supporting sea life. Seafood is very healthy because of its high mineral content.

Mineral-rich sea water also provides resources that are turned into products we use every day. For example, the ocean floor contains deposits of metals such as tin and gold. These metals form lumps at the bottom of the sea that can be picked up somewhat easily. Oil and natural gas beneath the ocean floor are other valuable resources. They can be pumped from bottom of the sea and used around the world for fuel.

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