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Education: Student Outcomes |
Click here to search for other assets Properties of Fresh & Sea Water Grade level: K-4 Theme: water cycle Activity: http://aquarius.nasa.gov/prop_fresh_sea.html Big Idea Water has unique properties. About 97 percent of all water is in the oceans. Salt water or seawater has characteristics similar to fresh water with some noticeable differences because of the salts that are dissolved in water.
Key Concepts Life on Earth is possible because of water's unique properties.
Water is the only natural substance that is found in all three states -- liquid, solid (ice), and gas (steam) -- at the temperatures normally found on Earth.
Water can absorb a tremendous amount of heat acting like a heat buffer for the Earth.
Background Liquid water (H2O) is often perceived to be pretty ordinary as it is transparent, odorless, tasteless and ubiquitous. Water is unique in that it is the only natural substance that is found in all three states -- liquid, solid (ice), and gas (steam) - at the temperatures normally found on Earth. Earth's water is constantly interacting, changing, and in movement. Water freezes at 32° Fahrenheit (F) and boils at 212° F (at sea level). In fact, water's freezing and boiling points are the baseline with which temperature is measured: 0° on the Celsius scale is water's freezing point, and 100° is water's boiling point. Water is unusual in that the solid form, ice, is less dense than the liquid form, which is why ice floats. Student Outcomes After completing this activity, students should be able to: Compare the basic properties of fresh and salt water (e.g., density, ability to dissolve salt, freezing point). (W: K-4) Key: C = climate / O = ocean circulation / T = 21st century technology / W = water cycle |
